Entire Report - February 2011


National Overview

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.

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Climate Division Dataset Transition

U.S. Climate Divisions

For years, the Climate Divisional Dataset was the only long-term temporally and spatially complete dataset from which to generate historical climate analyses (1895-2013) for the contiguous United States. Traditionally, the monthly values for all of the Cooperative Observer Network (COOP) stations in each division are averaged to compute divisional monthly temperature and precipitation averages/totals.

NCDC's Climate Monitoring Branch transitioned to a more modern 5km gridded divisional dataset in early 2014. This dataset is based on a similar station inventory as was the former dataaset. However, new methodologies are used to compute temperature, precipitation, and drought for United States climate divisions. These improve the data coverage and the quality of the dataset, while maintaining the current product stream. More detailed information on the transition and the resulting impacts can be accessed here: Gridded Division Dataset Transition.

While this transition did not disrupt the product stream, some variances in temperature, precipitation and drought values may be observed in the new data record. A visualization toolkit can help users examine snapshots of both datasets. Changes in monthly, seasonal and annual variability can be examined through the use of the interactive time series plots.

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National Overview:

February 2011 had a very active weather patternweather pattern over the contiguous United States. A high amplitude circulation (one with many troughs and ridges and low pressure sytems) dominated during the first part of the month, resulting in several winter storm systems moving across many parts of the country. Significant troughing occurred in the West early in the month, sending frigid Canadian air plunging into the Lower 48 States. By the 10th, the maximum national snow cover extent for the month, about 65 percent, was reached. Snow cover extent was the 9th largest for February for the contiguous U.S. and 8th largest for North America in the 45-year satellite snow cover extent record.

The pattern switched to a more zonal flow later in the month, with the storm track more along the northern states. Temperatures moderated when the circulation pattern flattened at mid-month, but the month ended with surges of cold air behind strong cold fronts, which brought severe weather and tornado outbreaks. There were 59 preliminary tornado reports during February 2011, ranking the month in the top ten busiest Februaries. Drought-stricken areas in the southeast received beneficial precipitation early in the month, but the shift of the storm track further north later in the month left the South dry while bringing relief to the Midwest and Ohio Valley. February ended with moderate-to-extreme drought covering 23 percent of the U.S., about 3 percent higher than at the end of January. Wildfire activity was high during the month, particularly across the South and Southeast, with a record high February number of wildfires and second highest for acres burned. The mid-month circulation shift was accompanied by a surge of winter storms into the West, whose rain and snow ended a one and a half month lull in precipitation. The month started with about half (52.2 percent) of the country covered in snow and ended with about half (49.5 percent) snowcovered. The circulation pattern flip-flop resulted in nationally-averaged temperature and precipitation ranks near the middle of the 117-year historical distribution (51st coolest and 41st driest February).

Weather systems are influenced by the broadscale atmospheric circulation. Two such large-scale atmospheric circulation patterns were dominant during February. The first was a weakening La Niña, which. at this time of year, is typically associated with dry conditions in the Southwest, Southeast, and southern Plains, a wet signal along the Ohio Valley and in the northern tier states, and warmer-than-normal temperatures across most of the country, especially in the Southwest. The second was the Pacific/North American (PNA) pattern, which transitioned from a near-neutral phase in early February to negative during the last half of the month. A negative PNA this time of year is typically associated with warmer-than-normal temperatures over the southeast third of the U.S., colder-than-normal temperatures in the Northwest, and wetter-than-normal conditions in the Pacific Northwest and from the Ohio Valley northward.


  • Climate Highlights - February
  • During the month's first half, a southward-plunging polar jet stream held temperatures as much as 15 degrees F below normal in much of the Central and Southern United States. Warm tropical air advanced northward across these regions during the second half of the month, and average temperatures reversed to nearly 15 degrees F above normal. This flip-flop resulted in near-normal temperatures for February as a whole.
  • Conditions were persistently warm throughout the entire month in the extreme Southeast, resulting in above normal averages for the region. Below average temperatures affected much of the western U.S
  • The precipitation pattern in February was well defined. Most of the Gulf and Atlantic Coast states experienced below average precipitation. It was the eighth driest February in Louisiana and Mississippi (tied 1954).
  • A continuous flow of moisture contributed to above normal precipitation in: Ohio (fifth wettest), South Dakota (sixth), and Indiana (tenth).
  • Two severe weather outbreaks during February's last week brought the month's preliminary tornado count to 59. The final tornado count for February 2011 will likely rank among the ten busiest Februaries on record.
  • The year-to-date period (January - February) was the ninth driest such period on record for the Contiguous United States. For the period, three times as many states had below normal precipitation than those with above normal. It was the second driest such period in Virginia, fourth driest in New Mexico, and seventh driest in North Carolina. Much of the west, south and southeast also had precipitation below the 20th century average.
  • Several record breaking snowstorms caused the U.S. to have above average snow cover extent during February. The "Groundhog Day Blizzard" dropped at least 5 inches of snow in 22 states. On February 10th, nearly two thirds of the contiguous U.S. was snow covered with every state except Florida having snow on the ground.
  • Dry conditions across the southern and southeastern U.S. were associated with much-above average wildfire activity during February. Across the country, 8,226 wildfires burned approximately 187,000 acres - the most February wildfires during the 21st Century and the second most acreage burned.
  • Drought coverage, as indicated by the U.S. Drought Monitor, continued to expand during February. As of March 1, 27.9 percent of the United States was affected by D1-D4 (Moderate-Exceptional) drought. Many of the areas that were experiencing drought at the beginning of February only saw conditions worsen through the end of the month. Across southern New Mexico, Arizona, and western Texas, drought conditions worsened from moderate to severe. Severe drought also expanded across the Front Range in Colorado and across central Oklahoma during the month. Severe and extreme drought expanded across most of Texas, and the footprint of extreme drought grew across the Lower Mississippi River Valley. Moderate drought conditions developed across northern Alabama and Mississippi and severe drought covered much of the Carolina piedmont.
  • Climate Highlights - December through February
  • The average winter temperature in the United States was 0.7 degrees F below the 20th century average. Much of the cooler than normal temperatures were confined to the regions east of the Rockies.
  • The majority of states, especially those east of the Rockies, were cooler than average during the winter period. Maine and Nevada were the only two states that averaged a temperature that was above normal. Georgia (3.9 degrees F below normal) and Florida (3.7 degrees F below normal) experienced the greatest departures from normal (or temperature anomalies) during the winter period.
  • Persistent dryness defined winter, especially in the South and Southeast climate regions where it was the third and ninth driest on record, respectively. Further north, the active weather pattern resulted in the eighth wettest winter season on record for the West North Central Climate Region.
  • Much unlike the previous winter, a persistent high pressure system in the Gulf of Mexico, prevented moisture-laden systems from entering the southern regions. This resulted in several states having a winter period among their driest ten percent on record. It was the third driest for Alabama, Louisiana, Mississippi, and North Carolina. Virginia had thier seventh driest such period.
  • Relentless precipitation in South Dakota and Montana resulted in their fourth and ninth wettest winter period, respectively.

Alaska Temperature and Precipitation:

  • Alaska had its 47th warmest February on record, with a temperature 0.7°F (0.4°C) above the 1971–2000 average.
  • Alaska had its 45th coolest December–February on record, with a temperature 0.4°F (0.2°C) below the 1971–2000 average.
  • Alaska had its 32nd warmest year-to-date period on record, with a temperature 2.3°F (1.3°C) above the 1971–2000 average.
  • Alaska had its 10th wettest February since records began in 1918, with an anomaly that was 85.8 percent above the 1971–2000 average.
  • Alaska had its 23rd wettest December–February on record, with an anomaly that was 23.4 percent above the 1971–2000 average.
  • Alaska had its 12th wettest year-to-date period on record, with an anomaly that was 45.0 percent below the 1971–2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below. For information on local temperature and precipitation records during the month, please visit NCDC's Records page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.


Regional Highlights:

These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.

  • Northeast Region: (Information provided by the Northeast Regional Climate Center)
  • Temperatures in the Northeast averaged just below normal in February. The region?s average of 25.6 degrees F (-3.6 degrees C) was -0.8 degrees F (-0.4 degrees C) below normal. It was the coolest February since 2007. Four states in the region, Delaware, Maryland, New Jersey, and West Virginia, averaged above normal with departures that ranged from +1.0 degrees F (+0.6 degrees C) in Delaware to +2.9 degrees F (+1.6 degrees C) in West Virginia. Temperature departures in the cooler-than-normal states ranged from -0.3 degrees F (-0.2 degrees C) in Pennsylvania to -3.1 degrees F (-1.7 degrees C) in New Hampshire. A warm-up during the third week of February sent readings 15 to 25 degrees F (8 to14 degrees C) above normal. A few new maximum temperature records were established, including a new high of 77 degrees F (25.0 degrees C) on the 18th at Washington National Airport, DC. The temperature average for the winter of 2010-2011 (December - February) was 24.2 degrees F (-4.3 degrees C), which was 2.0 degrees F (1.1 degrees C) below normal. Every one of the Northeast states except Maine were cooler than normal. Departures ranged from 1.2 degrees F (0.7 degrees C) above normal in Maine to 3.3 degrees F (1.8 degrees C) below normal in Delaware and Maryland.
  • On average, the Northeast saw 119 percent of the normal precipitation amount, or 3.22 inches (81.8 mm). The three southernmost states were drier than normal with departures of 88 percent in West Virginia, 75 percent in Maryland and 58 percent in Delaware. It was the 17th driest February in 117 years in Delaware. The states with above normal precipitation had departures that ranged from 104 percent in New Jersey to 143 percent in Pennsylvania, where it was the 17th wettest February since 1895. Precipitation totals for climatological winter were exactly normal. The range of departures among the states was 68 percent of normal in Delaware to 122 percent in Maine. It was the 10th driest winter in Delaware and the 16th driest in Maryland. Drier than normal conditions in the southern part of the region has led to drought concerns there. The March 1, 2011 U.S. Drought Monitor indicated that parts of West Virginia, Maryland, Delaware and Pennsylvania were abnormally dry, while extreme eastern West Virginia was in moderately drought (D1). In addition, small areas in northern New York, Vermont, and New Hampshire were abnormally dry.
  • The news-making winter storm that blasted through Chicago and the Midwest had plenty of energy remaining when it hit the Northeast on the 1st and 2nd. When the storm cleared out on the 3rd, eastern New York and New England had amassed an additional 6 to 12 inches (15 to 30 cm) of new snow on top of the 12-18 inches (30-46 cm) on the ground from storms in January. Sleet and freezing rain mixed in with the snow in some areas, adding to the weight of the snowpack. Besides the usual problems associated with a major storm, such as air travel delays and poor road conditions, the accumulated snow, sleet, and freezing rain caused ice dams on roofs, numerous roof collapses, and dangerous conditions from snow and ice falling off roofs in downtown areas. Once the reports of roof collapses began, many schools, stores and restaurants closed as a precaution until the snow could be cleared from the roofs. Damage to buildings and their contents from leaks and collapses are estimated to be in the millions. Just one roof collapse at a small airport hangar in Norwood, MA resulted in at least $1.1 million in damages to the aircraft inside.
  • For more information, please go to the Northeast Regional Climate Center Home Page.
  • Midwest Region: (Information provided by the Midwest Regional Climate Center)
  • February temperatures varied in both time and space. The second week of the month was cold and the third week warm across the region. Weeks one and four varied spatially giving a mix of temperature departures for the month. Departures varied from -4 degrees F ( 2 degrees C) to -6 degrees F (-3 degrees C) along the western edge of the region to 3 degrees F (2 degrees C) in southern Ohio and extreme eastern Kentucky. Winter temperatures were near normal in northern Michigan and Wisconsin and ranged from 2 degrees F (1 degrees C) to 5 degrees F (3 degrees C) below normal across most of the other Midwest states. February was the only winter month to report above normal temperatures for parts of the Midwest.
  • Midwest February totals included pockets of below normal precipitation but also large areas exceeding 200 percent of normal. The below normal areas were extreme eastern Kentucky, southwestern Iowa, and the northern quarter of the region. The driest area was the upper Midwest were totals were less than 50 percent of normal. Snowfall totals were also quite variable in February. Below normal snowfall totals, as much as 50 percent below normal, occurred in southern Indiana, southern Ohio, and eastern Kentucky as well as across the upper Midwest. Snowfall totals were above normal with totals exceeding 200 percent of normal over swaths from southern Minnesota to southern Michigan and from Missouri to northern Ohio. Totals approached 700 percent of normal in southwest Missouri. Monthly records for snowfall were set in Chicago, Illinois, Galesburg, Illinois, Lansing, Michigan, and Flint, Michigan. Almost 900 daily snowfall records were set across the Midwest during the month. Winter season snowfall totals were above normal for nearly all of the Midwest. Slightly below normal totals fell in northern Michigan while totals exceeded 200 percent of normal in parts of the other eight Midwest states. More than 2900 daily snowfall records occurred during the three-month winter season. Winter season snowfall records were set in Peoria, Illinois and Rochester, Minnesota.
  • Numerous storms affected the Midwest in February. A blizzard hit the region on the 1st and 2nd of the month and another snowstorm followed just days later. On the 9th and 10th a big storm moved out of the southern plains and across southern Missouri and Kentucky leaving snow and very cold temperatures in its wake. A big thaw event began mid-month and lasted through the third week of the month. The thaw melted most of the Midwest snow except in Minnesota, Wisconsin, Upper Michigan, and northern Iowa where snow depths remained in excess of 12 inches (30 cm). Winter weather returned on the 20th and 21st as a system swept out of the Dakotas, across southern Minnesota to southern Michigan and northern Ohio. On the 24th and 25th a storm dropped snow from west to east across the middle of the Midwest. The last three days of the month saw the final system that not only dropped snow in the north but also brought severe weather to the central and southern parts of the Midwest.
  • At least 15 tornadoes were confirmed in Missouri (1), Illinois (2), Indiana (6), Kentucky (5), and Ohio (1) on the 27th and 28th. Among the strongest was an EF3 rated storm in Henry County, Kentucky. Along with the tornadoes and hail, the storms brought heavy downpours, measured in excess of 5 inches (127 mm) in parts of Indiana, Kentucky, and Ohio. Flooding was widespread in those states and five people died in two incidents of vehicles washed into flooded waterways. Four children died in Graves County, Kentucky when their buggy was overturned in the raging waters of a normally tiny creek and a woman died in Norwalk, Ohio when her car was pushed into the Huron River by floodwaters.
  • For details on the weather and climate events of the Midwest, see the weekly summaries in the MRCC Midwest Climate Watch page.
  • Southeast Region: (Information provided by the Southeast Regional Climate Center)
  • Mean temperatures were above normal across the Southeast in February. Temperatures were 3 to 5 degrees F (1.6 to 2.8 degrees C) above normal across the interior of the region and 1 to 3 degrees F (0.5 to 1.6 degrees C) above normal along the coasts. Mean temperatures were near normal across Puerto Rico, while the U.S. Virgin Islands experienced their fourth consecutive month of below normal temperatures. The cold weather that dominated the region in December and January continued into early February, particularly across parts of Alabama and Florida. However, temperatures rebounded significantly during the second half of the month as the Arctic Oscillation transitioned to a positive phase and more southerly and westerly winds became established over the Southeast. Columbia, SC and Charlotte, NC tied their all-time February maximum temperature records of 84 degrees F (28.9 degrees C) on the 28th of the month and 82 degrees F (27.8 degrees C) on the 27th of the month, respectively. For the month, Charlotte, NC recorded nine days of 70 degree F (21.1 degrees C) temperatures or greater, which is the most ever for February in a record extending back to 1875. Raleigh-Durham, NC surpassed 80 degrees F (26.7 degrees C) twice in February, which tied the previous record set in 1989. Despite a return to warm temperatures in February, mean temperatures during meteorological winter (December-February) ranked among the top 5 coldest in many locations across the region. Wilmington, NC recorded its second coldest winter in a record extending back to 1871, while Jacksonville, FL recorded its fifth coldest winter in a record extending back to 1870.
  • Mean precipitation for the Southeast region was slightly below normal in February, though there was much local variability. There were two relatively narrow corridors of above normal precipitation (125 to 150 percent), one that cut across the eastern Panhandle of Florida and one that stretched across southern Alabama, central Georgia, and eastern portions of the Carolinas. Much of this precipitation was tied to a series of storms that crossed the region on the 4th and 5th of the month. The driest locations (less than 25 percent of normal) were found in the southern half of Florida with some locations recording less than 5 percent of normal precipitation for the month. Most notably, Key West, FL recorded only 0.01 inches (0.25 mm) of precipitation for the month, making it the second driest February in a record extending back to 1871. Elsewhere across the Southeast, monthly precipitation was generally between 50 and 75 percent of normal.
  • There were 214 reports of severe weather across the Southeast in February, including nine confirmed tornadoes. Most of these occurred on the 28th of the month, as a line of strong storms spawned six tornados across Alabama and the Carolinas. A weak tornado was reported along I-40 in Iredell County, NC, while an EF-1 tornado was reported in Newberry County, SC. Four separate tornadoes were also reported in Alabama. The strongest was an EF-1 that snapped large hardwood trees and destroyed at least one home in Lowndes County. Large hail and damaging straight-line winds were also reported in Georgia. This severe weather outbreak resulted in tens of thousands of power outages across the region.
  • Light to moderate snowfall occurred across a large portion of the Southeast from the 9th to the 11th of the month as a weak area of low pressure tracked along the Gulf and Atlantic coasts. Snowfall totals of up to 3 inches (76.2 mm) were reported across northern portions of Alabama and Georgia, while over 4 inches (101.6 mm) of snow was reported across eastern sections of North Carolina and Virginia. Many other locations in central Alabama, Georgia, and the Carolinas reported less than 1 inch (25.4 mm) of snow from this event, while coastal sections of the Carolinas, including Wilmington, NC, and Conway, SC, reported ice pellets mixed with light snow.
  • The lack of precipitation in February resulted in the emergence of severe (D2) and extreme (D3) drought conditions across the northern half of Alabama and southeastern Florida, respectively. However, the beneficial rains through portions of central Georgia and South Carolina resulted in a reduction from severe drought to moderate drought (D1) conditions in those areas. The warm temperatures near the end of the month caused many of the peach and blueberry crops to bloom across Georgia, making them especially vulnerable to a killing frost. According to the Georgia State Climate Office, a killing frost could have an economic impact of over $150 million to the industry. In addition to the warm temperatures, a combination of high winds, dry soils, ample leaf litter, and low relative humidity created ideal conditions for wildfires across much of the Southeast. In North Carolina, the Division of Forest Services reported over 12,000 fires across the state in February and more than 1,700 acres burned.
  • For more information, please go to the Southeast Regional Climate Center Home Page.
  • High Plains Region: (Information provided by the High Plains Regional Climate Center)
  • February 2011 was a month of extremes in the High Plains Region. The lowest temperatures of the month were, for the most part, observed at the beginning of the month. An arctic air mass settled into the Region and many daily low temperature records were set. Dangerous wind chills were also experienced throughout the Region. According to the National Weather Service in Cheyenne, Wyoming, the coldest wind chill in that area was -61 degrees F (-51.7 degrees C) at the Laramie Airport on February 2. Also on that date, the Rawlins Municipal Airport, Wyoming tied its all time lowest temperature record when the temperature plummeted to -36 degrees F (-37.8 degrees C). The all-time record is shared with 2/6/1989, 1/4/1973, and 1/19/1963 (period of record 1951-2011). There was a warm-up mid month and daily high temperature records were broken in parts of Colorado, Kansas, Nebraska, and South Dakota but the month ended on the chilly side as cold air quickly moved back into the Region.
  • Overall, February average temperatures were 2-6 degrees F (1.1-3.3 degrees C) below normal for most of the Region including Kansas, Colorado, the eastern Dakotas, and eastern Nebraska. Large areas of western North Dakota, central and western South Dakota, the panhandle of Nebraska, and central and eastern Wyoming had average temperatures which were more than 6 degrees F (3.3 degrees C) below normal. The cold weather allowed many locations to break into the top 20 coldest Februaries on record. In addition, locations in Wyoming and the panhandle of Nebraska had average monthly temperatures which ranked in the top 10 coldest Februaries on record. Sunshine 3NE, Wyoming, which is located in the northwest part of the state, had its 2nd coldest February on record with an average temperature of 15.0 degrees F (-9.4 degrees C). The record of 11.0 degrees F (-11.7 degrees C) was recorded in 1989 (period of record 1963-2011).
  • Several storm systems affected the Region this month. Overall, South Dakota, eastern Kansas, and pockets of both Colorado and Wyoming had precipitation which was above normal. The rest of the Region had either near to below normal precipitation. A strong system brought extreme cold and snow to the Region at the beginning of the month. While many locations within the Region received snowfall, the main impacts of the storm were just east of the Region. A large area from Kansas City through Chicago was hit particularly hard as dangerous blizzard conditions led to interstate and airport closures. Another round of snow hit the eastern portion of the Region on February 8-9. The heaviest snow fell in eastern Kansas where up to 16 inches (41 cm) was reported. A mid-month warm-up allowed for much of the snow cover across the Region to melt, however the snow cover quickly built up again. Later in the month a storm system moved through the Region bringing thunderstorms, ice, and snow. On the 21st, thunderstorms occurred in eastern Nebraska while just to the north, ice accumulations up to a quarter inch were reported. Meanwhile, heavy snow fell across South Dakota, where over a foot (30 cm) of snow was reported in many locations. On February 24th another snow storm hit the Region. Heavy snows of up to a foot (30 cm) were again reported in southwestern South Dakota and up to 5-9 inches (13-23 cm) were reported in Kansas and Nebraska. Also, in Kansas and Nebraska, much of the snow fell in a short amount of time and snowfall rates of 2 inches/hour (5 cm/hour) were reported. The month ended with the first round of severe storms to hit the Region. On February 27th thunderstorms produced large hail in southern Kansas and a brief tornado was spotted along the Kansas-Oklahoma border.
  • The heavy snow this month not only led to new February records but also new winter (December, January, and February) records. Bonner Springs, Kansas, which is just outside of Kansas City, recorded its snowiest February on record with 17.5 inches (44 cm) of snowfall (period of record 1938-2011). The old record was set in 1978 with 17.0 inches (43 cm). Aberdeen, South Dakota had its 4th snowiest February with 21.0 inches (53 cm) and its snowiest winter with 61.2 inches (155 cm) of snow (period of record 1893-2011). This beat the longstanding record of 57.0 inches (145 cm) which was set in 1915.
  • Meanwhile, North Dakota was on the dry side this month. Fargo, North Dakota only received 0.08 inches (2 mm) of liquid equivalent precipitation which was the 6th driest February on record and Grand Forks, North Dakota only received 0.04 inches (1 mm) of liquid equivalent precipitation which was the 4th driest February on record. The dry conditions this month did not stop the concern over flooding along the Red River or flood preparations. According to the North Dakota State Climate Office, Fargo had already filled 1.5 million sand bags and the North Dakota National Guard began training sessions to help prepare for the potential flooding.
  • The U.S. Drought Monitor did not change over the last month for the High Plains Region. Severe drought conditions (D2) persisted over south-central Colorado and western Kansas. A large area of moderate drought conditions (D1) across eastern Colorado, western Kansas, and the panhandle of Nebraska also remained. A second area of D1 in southeastern Kansas also existed. In addition, the areas of abnormally dry conditions (D0) in western Wyoming and surrounding the D1 areas remained unchanged. According to the U.S. Seasonal Drought Outlook released February 17th drought conditions across Colorado, Kansas, and Nebraska were expected to persist and drought conditions were expected to develop in southern Nebraska and central Kansas.
  • For more information, please go to the High Plains Regional Climate Center Home Page.
  • Southern Region: (Information provided by the Southern Regional Climate Center)
  • February average temperatures in the Southern Region varied spatially from west to east. In the north western areas of the region, temperatures were generally 2 to 6 degrees F (1.11 to 3.33 degrees C) below the monthly normal. In Tennessee in Mississippi, however; temperatures averaged between 2 to 6 degrees F (1.11 to 3.33 degrees C) above the monthly normal. Elsewhere, temperatures remained within approximately 2 degrees F (1.11 degrees C) of the monthly expected values. The state average temperatures in the region were: 43.80 degrees F (6.56 degrees C) in Arkansas, 52.40 degrees F (11.33 degrees C) in Louisiana, 49.30 degrees F (9.61 degrees C) in Mississippi, 40.20 degrees F (4.56 degrees C) in Oklahoma, 43.30 degrees F (6.28 degrees C) in Tennessee and 49.20 degrees F (9.56 degrees C) in Texas. All state value temperature rankings fell within the two middle quartiles of the normal distribution as based on the 1895-2011 period of record.
  • With the exception of central and northern Arkansas, northern Tennessee and north eastern Oklahoma, the month of February was a dry month for the Southern Region. The driest areas of the region included much of southern and south western Texas, where most stations received less than a quarter of the monthly normal precipitation total. In central Louisiana and southern Mississippi, the majority of stations reported precipitation totals that ranged between 25 and 50 percent of normal. Similar conditions were also observed throughout parts of central Texas and north western Oklahoma. The wettest area of the region included much of north central Arkansas where stations reported between 150 and 400 percent of normal precipitation. On February 9-10, 2011, many areas of Oklahoma received heavy snowfall accumulations. Accumulations varied from few a few inches to over two feet in the north eastern portions of the state. For instance, the station at Spavinaw, Oklahoma received 27 inches (685.80 mm) of snowfall in a 24 hour period. The state-wide average precipitation totals for the month were as follows: 4.17 inches (105.92 mm) in Arkansas, 2.04 inches (51.82 mm) in Louisiana, 2.14 inches (54.36 mm) in Mississippi, 1.35 inches (34.29 mm) in Oklahoma, 3.66 inches (92.96 mm) in Tennessee and 0.66 inches (16.76 mm) in Texas. For Louisiana, it was the eighth driest February on record (1895-2011), while for Mississippi, it was the fourth driest on record (1895-2011). Another rank worth mentioning was in Texas, which experienced its seventeenth driest February on record (1895-2011).
  • Drier than normal conditions throughout most of the Southern Region has led to an expansion of drought in many areas. Most notably, there was an expansion of extreme drought in central and northern Louisiana and in eastern Texas. South western Texas also experienced a slight expansion of extreme drought. On February 1, 2011, only 6.59 percent of the Southern Region was experiencing extreme drought. One month later, on March 1, 2011, that number has increased to 10.76 percent. In Mississippi, the entire state is now classified in moderate drought or worse. In fact, almost three quarters of the Southern Region is now in moderate drought or worse, compared to 58.97 percent of the region the previous month.
  • On the first day of the month, two tornadoes were reported. One occurred in Rusk County, Texas where two homes were damaged. The other occurred in Sabine Parish, Louisiana. Minor home damage was indicated. On this day there were also several wind reports throughout central Louisiana, southern Mississippi. Damage from the strong winds was mostly restricted to tree and power line damage.
  • On the twenty-fourth of the month, several tornadoes were reported over an area that includes western Tennessee, northern Mississippi, central Arkansas, eastern Arkansas and northern Louisiana. In Lonoke County, Arkansas, a large metal building had two doors blown in. There was also widespread damage reported to trees and power lines. A mobile home was destroyed, and grain bins were pulled off the concrete in Decatur County, Tennessee. In Davidson County, Tennessee, substantial structural damage was reported to homes in the Percy Priest Lake Area. Strong winds in Webster Parish, Louisiana led to one reported injury. The injury was the result of a tree falling on a truck.
  • On the twenty-eighth of the month, several tornadoes were reported across south central Tennessee and central Mississippi. In Moore County, Tennessee, one person was killed and four others were injured. In Franklin County, Tennessee, one tornado-related death was reported. Strong winds in Polk County, Tennessee caused one fatality when a tree fell on a mobile home.
  • On February 9 to 10, 2011, A winter storm produced heavy snowfall accumulations and freezing temperatures throughout the state of Oklahoma. Snowfall accumulations varied from a few inches to over two feet (609.56 mm) of snow. The snowfall resulted in school and road closures and an extension of a state of emergency that was initially issued earlier in the month. In terms of temperatures, many stations reported record low temperatures that ranged from -20 degrees F (-28.89 degrees C) to -31 degrees F (-35 degrees C). The latter was reported at the Oklahoma University Mesonet station in Nowata, Oklahoma. Another example of the extreme temperatures were at the Ralston and Bartlesville stations, which reported temperatures of -29 degrees F (-33.89 degrees C) and -28 degrees F (-33.33 degrees C), respectively.
  • For more information, please go to the Southern Regional Climate Center Home Page.
  • Western Region: (Information provided by the Western Regional Climate Center)
  • Temperatures were below to well below normal throughout the entire West except for a small region from northeast Nevada to northern Utah and a few other isolated pockets. The month began with record setting cold from Montana to New Mexico. A stretch of mild weather prevailed for a week mid month before another very cold episode the final week. Many locations in the region were up to 5 degrees F (2.8 C) below normal while some locations in Montana were 10 degrees F (5.8 C) below normal for the month. Some cities in Southern California recorded their coldest February in over 30 years. Santa Barbara CA had their third coldest February on record dating back 70 years. Great Falls, MT, measured their coldest February in 22 years. Some cities in the southwest recorded their lowest all time February temperatures early in the month (see below).
  • Precipitation was below normal for most of the west except for isolated pockets in the intermountain region. Great Falls' extreme month continued with their second wettest and most snowy February in 119 years and third all time snowiest month. The only other record setting precipitation occurred in the far north where Fairbanks, AK, measured their second wettest and second snowiest February on record. Barrow also had their third wettest and second snowiest February ever.
  • Thanks to a stormy second half of the month mountain snowpack was mostly above normal on March 1st except for some areas of the Southwest and the Pacific Northwest, although the precipitation totals in the higher elevations of the Northwest are actually above normal.
  • The extreme cold that settled in the Southwest during the first few days of the month set numerous records and caused widespread damage. It was estimated that in El Paso, TX, over 15,000 pipes broke with damage at over $50 million. Albuquerque recorded their lowest February maximum temperature (and second lowest ever) with 9 F (-12.8 C) on the 2nd. In addition, the minimum of -7 F (-21.7 C) was the second coldest February temperature on record. In Douglas, AZ, a minimum of 0 F (-17.8 C) on the 4th set an all time February mark and was only the third time in history the city has reached 0 F (-17.8 C). The lows at Tucson, AZ of 18 F (-7.8 C) on the 3rd and 4th were not only their coldest February temperature on record but only 2 degrees F (1.1 C) away from their all time low. Roswell, NM, hit -11 F (-23.9 C) on the 4th, which was the coldest February temperature since 1933 and coldest for any month since 1966. Laramie, WY, hit a new February low of -39 F (-39.4 C) on the 2nd as well, in a record dating back to 1948. Roughly 32,000 residents in New Mexico and 14,000 in Arizona had no natural gas on the 4th due to shortages brought on by the extreme cold.
  • A cold and powerful system affected nearly the entire west. The Seattle area had up to 3 inches (7.6 cm) of snow on the 23rd with wind chills in Montana as low as -50 F (-45.5 C) on the 25th. Cut Bank, MT, fell to -35 F (-37.3 C) on the 25th, the coldest temperature ever recorded for so late in the season. This system produced rare snow in Tucson, AZ, and the hills of the San Francisco Bay Area in California.
  • Strong offshore winds produced wind gusts of near 95 mph near Valdez, AK, causing flying debris to shatter car windows and siding being blow off buildings. The Port of Valdez was closed on the 27th as oil tankers had to be held in protected areas of the Prince William Sound. At Thompson Pass 100 mph winds produced blizzard conditions that forced the closure of the Richardson Highway, the only road out of or into Valdez.

See NCDC's Monthly Records web-page for weather and climate records for the most recent month. For additional national, regional, and statewide data and graphics from 1895-present, for any period, please visit the Climate at a Glance page.


PLEASE NOTE: All of the temperature and precipitation ranks and values are based on preliminary data. The ranks will change when the final data are processed, but will not be replaced on these pages. Graphics based on final data are provided on the Temperature and Precipitation Maps page and the Climate at a Glance page as they become available.

Global Analysis

Contents of this Section:


February 2011 Selected Climate Anomalies and Events MapFebruary 2011 Selected Climate
Anomalies and Events Map

Global Highlights

  • The combined global land and ocean average surface temperature for February 2011 was 0.40°C (0.72°F) above the 20th century average of 12.1°C (53.9°F). This ties for the 17th warmest such value on record.

  • The combined global land and ocean average surface temperature for December 2010 – February 2011 was 0.39°C (0.70°F) above the 20th century average of 12.1°C (53.8°F), the 16th warmest such period on record.

  • For the year to date, the combined global land and ocean surface temperature of 12.49°C (54.50°F) was the 16th warmest January–February period on record. This value is 0.39°C (0.70°F) above the 20th century average.

  • The worldwide land surface temperature for February 2011 tied as the 28th warmest February on record, at 0.51°C (0.92°F) above the 20th century average of 3.2°C (37.8°F). The February 2011 Northern Hemisphere land temperature was the 30th warmest, while the Southern Hemisphere tied as the 25th warmest on record.

  • The seasonal (December 2010 – February 2011) worldwide land surface temperature was the 26th warmest on record, 0.45°C (0.81°F) above the 20th century average of 3.2°C (37.8°F). The 2010–2011 seasonal Northern Hemisphere land temperature was the 28th warmest, while the Southern Hemisphere was 18th warmest on record.

  • The worldwide ocean surface temperature for February 2011 tied as the 10th warmest February on record, at 0.36°C (0.65°F) above the 20th century average of 15.9°C (60.6°F). The 2010–2011 seasonal Northern Hemisphere ocean temperature tied as the the 9th warmest, while the Southern Hemisphere was 12th warmest on record.

  • The seasonal (December 2010 – February 2011) worldwide ocean surface temperature tied as the 10th warmest on record, at 0.36°C (0.65°F) above the 20th century average of 15.8°C (60.5°F). The 2010–2011 seasonal Northern Hemisphere ocean temperature was the 8th warmest, while the Southern Hemisphere was 15th warmest on record.

Please Note: The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. Effective with the July 2010 State of the Climate Report, NCDC transitioned to the new version (version 3b) of the extended reconstructed sea surface temperature (ERSST) dataset. ERSST.v3b is an improved extended SST reconstruction over version 2. For more information about the differences between ERSST.v3b and ERSST.v2 and to access the most current data, please visit NCDC's Global Surface Temperature Anomalies page.

==global-temps-errata==

Introduction

Temperature anomalies for February 2011 and December 2010 – February 2011 are shown on the dot maps below. The dot maps on the left provide a spatial representation of anomalies calculated from the Global Historical Climatology Network (GHCN) dataset of land surface stations using a 1961–1990 base period. The dot maps on the right are a product of a merged land surface and sea surface temperature (SST) anomaly analysis developed by Smith et al. (2008). For the merged land surface and SST analysis, temperature anomalies with respect to the 1971–2000 average for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCDC's Global Surface Temperature Anomalies page.

February

The combined global land and ocean surface temperature for February 2011 tied with 1997 as the 17th warmest February since records began in 1880. The combined global land and ocean temperature anomaly was 0.40°C (0.72°F) above the 20th century average. Sea surface temperatures (SST) during February 2011 were warmer than average across much of the world's oceans. La Niña weakened during February 2011, although SSTs remained below normal across the central and eastern equatorial Pacific Ocean. According to NOAA's Climate Prediction Center (CPC), La Niña will continue to have global impacts but ENSO-neutral conditions are expected by June 2011. The February 2011 worldwide ocean SST tied with 1995 and 1998 as the 10th warmest on record, 0.36°C (0.65°F) above the 20th century average of 15.9°C (60.6°F).

The worldwide land surface temperature tied with 2005 as the 28th warmest February on record, at 0.51°C (0.92°F) above the 20th century average. During February 2011, warmer-than-average temperatures were present across large portions of the world's land areas, with the warmest anomalies covering most of Asia, central Africa, northern Alaska, and southern Greenland. Cooler-than-average regions included Eastern Europe, western Russia, and eastern Siberia.

February 2011 for the Northern Hemisphere combined land and ocean was the 20th warmest February on record. Separately, the Northern Hemisphere land ranked as the 30th warmest February, while the Northern Hemisphere ocean tied with 1997, 2001, and 2009 as the 9th warmest on record.

The February 2011 average temperature for the Southern Hemisphere as a whole (land and ocean surface combined) was 0.38°C (0.68°F) above the 20th century average—the 14th warmest February on record. The Southern Hemisphere land-only temperature during February 2011 tied with five other years as the 25th warmest February on record. The February 2011 Southern Hemisphere ocean temperature was the 12th warmest February on record.

In Australia, the average monthly maximum temperature was much cooler than normal. According to the Australian Bureau of Meteorology (BoM), Australia experienced its fifth coolest February maximum temperatures in the 62-year period of record, at 1.36°C below average. Western Australia had its third coolest February maximum temperatures, at 2.22°C below average, and the Northern Territory was 2.27°C below normal, the seventh coolest maximum temperatures on record and coolest since 1993. The summer (December–February) was the country's coolest since 2001. The cooler temperatures can be attributed in part to an ongoing La Niña event that brought heavy rainfall to much of Australia.

Season (December–February)

The combined global land and ocean surface temperature during December 2010 – February 2011 ranked as the 16th warmest boreal winter (austral summer) on record. During the three-month season, warmer-than-average conditions were particularly felt across western Alaska, eastern Canada, southern Greenland, and northern Siberia. Cooler-than-average regions included Eastern Europe, western Russia, and Mongolia. The seasonal temperature for the worldwide land surface ranked as the 26th warmest December–February on record, at 0.45°C (0.81°F) above the 20th century average. The worldwide ocean surface temperature tied with 1997–1998 as the 10th warmest December–February temperature on record.

The Northern Hemisphere combined land and ocean surface temperature during December 2010 – February 2011 tied with 1957–1958 as the 15th warmest on record. Separately, the Northern Hemisphere land temperature was the 28th warmest December–February on record, while the Northern Hemisphere ocean temperature was the 8th warmest on record.

The Southern Hemisphere combined land and ocean temperature during the three-month period was also the 15th warmest December–February on record, tying with 1994–1995. The Southern Hemisphere land temperature was the 18th warmest December–February on record, while the Southern Hemisphere ocean temperature was the 15th warmest December–February period on record.

Year-to-date (January–February)

The January–February 2011 Blended Land and Ocean Surface Temperature Anomalies in degree CelsiusJanuary–February 2011 map of temperature anomalies shows the presence of warmer-than-average conditions across most of the globe's surface area; however, notably cooler-than-average conditions were present across most of the United States, Europe, western Russia, southern China, much of Australia, the eastern and central Pacific Ocean, and the southern oceans. The combined global land and ocean surface temperature for the year-to-date period tied with 2000 as the 16th warmest January–February period on record. This value is 0.39°C (0.70°F) above the 20th century average.

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The average position of the upper-level ridges of high pressure and troughs of low pressure (depicted by positive and negative 500-millibar height anomalies on the February 2011 height and anomaly mapFebruary 2011 map and December 2010 – February 2011 height and anomaly mapDecember 2010 – February 2011, respectively) are generally reflected by areas of positive and negative temperature anomalies at the surface, respectively. For other Global products, please see the Climate Monitoring Global Products page.

Images of sea surface temperature conditions are available for all weeks during 2011 from the weekly SST page.


Temperature Rankings and Graphics

Current Month | Seasonal | Year-to-date

February Anomaly Rank
(out of 132 years)
Warmest on Record
°C °F Year °C °F
Global
Land +0.51 ± 0.31 +0.92 ± 0.56 28th warmest* 2002  +1.60 +2.88
Ocean +0.36 ± 0.07 +0.65 ± 0.13 10th warmest* 1998  +0.56 +1.01
Land and Ocean +0.40 ± 0.10 +0.72 ± 0.18 17th warmest* 1998  +0.83 +1.49
Northern Hemisphere
Land +0.61 ± 0.33 +1.10 ± 0.59 30th warmest 2002  +2.12 +3.82
Ocean +0.31 ± 0.08 +0.56 ± 0.14 9th warmest* 1998  +0.55 +0.99
Land and Ocean +0.42 ± 0.17 +0.76 ± 0.31 20th warmest 2002  +1.06 +1.91
Southern Hemisphere
Land +0.24 ± 0.06 +0.43 ± 0.11 25th warmest* 2010  +1.04 +1.87
Ocean +0.41 ± 0.06 +0.74 ± 0.11 12th warmest 1998  +0.58 +1.04
Land and Ocean +0.38 ± 0.06 +0.68 ± 0.11 14th warmest* 2010  +0.64 +1.15

*Signifies a tie

* Global Land tied with 2005 as 28th warmest on record.
* Global Ocean tied with 1995 and 1998 as 10th warmest on record.
* Global Land and Ocean tied with 1997 as 17th warmest on record.
* Northern Hemisphere Ocean tied with 1997, 2001, and 2009 as 9th warmest on record.
* Southern Hemisphere Land tied with 1942, 1988, 1995, 1997, and 2002 as 25th warmest on record.
* Southern Hemisphere Land and Ocean tied with 1992 as 14th warmest on record.

December–February Anomaly Rank
(out of 132 years)
Warmest on Record
°C °F Year °C °F
Global
Land +0.45 ± 0.18 +0.81 ± 0.32 26th warmest 2007  +1.36 +2.45
Ocean +0.36 ± 0.07 +0.65 ± 0.13 10th warmest* 1998  +0.57 +1.03
Land and Ocean +0.39 ± 0.09 +0.70 ± 0.16 16th warmest 2007  +0.71 +1.28
Northern Hemisphere
Land +0.49 ± 0.22 +0.88 ± 0.40 28th warmest 2007  +1.61 +2.90
Ocean +0.35 ± 0.08 +0.63 ± 0.14 8th warmest 1998  +0.55 +0.99
Land and Ocean +0.40 ± 0.13 +0.72 ± 0.23 15th warmest* 2007  +0.92 +1.66
Southern Hemisphere
Land +0.35 ± 0.07 +0.63 ± 0.13 18th warmest 2010  +0.83 +1.49
Ocean +0.38 ± 0.07 +0.68 ± 0.13 15th warmest 1998  +0.60 +1.08
Land and Ocean +0.38 ± 0.07 +0.68 ± 0.13 15th warmest* 1998  +0.62 +1.12

*Signifies a tie

* Global Ocean tied with 1997–1988 as 10th warmest on record.
* Northern Hemisphere Land and Ocean tied with 1957–1958 as 15th warmest on record.
* Southern Hemisphere Land and Ocean tied with 1994–1995 as 15th warmest on record.

January–February Anomaly Rank
(out of 132 years)
Warmest on Record
°C °F Year °C °F
Global
Land +0.48 ± 0.22 +0.86 ± 0.40 25th warmest* 2002  +1.43 +2.57
Ocean +0.36 ± 0.07 +0.65 ± 0.13 10th warmest* 1998  +0.56 +1.01
Land and Ocean +0.39 ± 0.09 +0.70 ± 0.16 16th warmest* 2002  +0.72 +1.30
Northern Hemisphere
Land +0.52 ± 0.27 +0.94 ± 0.49 29th warmest 2002  +1.89 +3.40
Ocean +0.33 ± 0.08 +0.59 ± 0.14 8th warmest* 1998  +0.55 +0.99
Land and Ocean +0.40 ± 0.15 +0.72 ± 0.27 17th warmest* 2002  +0.96 +1.73
Southern Hemisphere
Land +0.37 ± 0.07 +0.67 ± 0.13 17th warmest* 2010  +0.93 +1.67
Ocean +0.39 ± 0.06 +0.70 ± 0.11 13th warmest* 1998  +0.58 +1.04
Land and Ocean +0.38 ± 0.06 +0.68 ± 0.11 15th warmest 2010  +0.62 +1.12

*Signifies a tie

* Global Land tied with 1963 as 25th warmest on record.
* Global Ocean tied with 2001 and 2009 as 10th warmest on record.
* Global Land and Ocean tied with 2000 as 16th warmest on record.
* Northern Hemisphere Ocean tied with 1995 as 8th warmest on record.
* Northern Hemisphere Land and Ocean tied with 1944 as 17th warmest on record.
* Southern Hemisphere Land tied with 1987 as 17th warmest on record.
* Southern Hemisphere Ocean tied with 1999 as 13th warmest on record.

The most current data may be accessed via the Global Surface Temperature Anomalies page.

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Precipitation

The maps below represent anomaly values based on the GHCN dataset of land surface stations using a base period of 1961–1990. During February 2011, above-average precipitation fell over areas that included much of Australia (particularly the north), Mauritius, and parts of South America. The areas with the driest anomalies during February 2011 were observed across several islands in the central Pacific Ocean, parts of Brazil, and eastern Australia.

During the seasonal period December 2010 – February 2011, above-average precipitation fell over areas that included most of Australia, Borneo, Samoa, and parts of coastal Brazil. The driest anomalies during December 2010 – February 2011 were observed across in parts of the southeastern United States, French Polynesia, southern Pakistan, Canada's northern Pacific coast, and islands in the central Pacific Ocean.

According to the Australian Bureau of Meteorology (BoM), nationally averaged precipitation during February was the second highest in the 112-year period of record, at 76 percent above normal. South Australia recieved its highest monthly February rainfall on record (414 percent above average), while Western Australia received its second highest (130 percent above average). Several tropical and ex-tropical storms contributed to the wet weather in the north, while remnants of the storms interacted with several cold fronts in the south to produce heavy rains. Seasonally, Australia had its second wettest summer (Northern Hemisphere winter) on record, at 70 percent above average, with all states reporting above-average rainfall. Victoria received its highest summer rainfall on record, while Western Australia and South Australia experienced their second and third wettest summers. The wet conditions led to major flooding in parts of Queensland, New South Wales, Victoria, and Tasmania. La Niña contributed to the anomalous wet weather, along with several tropical cyclones. The above-average cyclone season in this region is typical during a La Niña event.

Additional details on flooding and drought events around the world can also be found on the February 2011 Global Hazards page.

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References

Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global Historical Climatology Network Database. Bull. Amer. Meteorol. Soc., 78, 2837-2849.

Quayle, R.G., T.C. Peterson, A.N. Basist, and C. S. Godfrey, 1999: An operational near-real-time global temperature index. Geophys. Res. Lett., 26, 333-335.

Smith, T.M., and R.W. Reynolds (2005), A global merged land air and sea surface temperature reconstruction based on historical observations (1880-1997), J. Clim., 18, 2021-2036.

Smith, et al (2008), Improvements to NOAA's Historical Merged Land-Ocean Surface Temperature Analysis (1880-2006), J. Climate., 21, 2283-2293.

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Global Hazards

Please note: Material provided in this report is chosen subjectively and included at the discretion of the National Climatic Data Center (NCDC). The ability to report on a given event is limited by the amount of information available to NCDC at the time of publication. Inclusion of a particular event does not constitute a greater importance in comparison with an event that has not been incorporated into the discussion. Data included in this report are preliminary unless otherwise stated. Links to supporting information are valid at the time of publication, but they are not maintained or changed after publication.


Updated 7 March 2011


1-3 FebruaryRecord breaking snow storm impacts the Central U.S. read more 4 FebruaryRare snowfall in Dallas, Texas causes travel hassles read more 1-6 FebruaryHeavy rains continue in Sri Lanka, affecting 1.25 million people read more 3-4 FebruaryRecord cold temperatures in northern Mexico kills six people and 35 zoo animals read more 3 FebruarySevere Tropical Cyclone Yasi makes landfall in Australia, causes 3.5 billion U.S. dollars worth of damage read more i 6-8 FebruaryWildfires in Western Australia damages over 100 buildings near Perth read more 4-6 FebruaryThe remnants of Tropical Cyclone Yasi causes flooding in the Australian state of Victoria read more 8 FebruaryDangerous smog levels engulf Madrid, Spain read more 11-14 FebruaryRecord snow hits the Korean Peninsula read more 14 FebruaryTropical Cyclone Bingiza makes landfall in Madagascar, killing six read more 14-17 FebruaryTropical Cyclone Carlos brings record rainfall to Darwin, Australia read more 8-9 FebruaryHeavy snow and bitter cold temperatures impact the south-central U.S. read more FebruaryWarm temperatures causes snow melt across Afghanistan, resulting in flooding of agricultural lands read more February 24-27Flooding and landslides in Bolivia kill 45 and leave 10,000 homeless read more



Drought conditions

Western Australia Fires
Western Australia Fires 6 February
Image Credit: NOAA ESRL

In contrast to the eastern portions of Australia, Western Australia suffered from dry conditions and wildfires during the first part of February. Between February 6th and 8th a large wildfire burned on the outskirts of Perth, destroying 71 buildings and damaging another 32. Strong sustained winds of 20 mph (30 km/h) and gusts as high as 40 mph (64 km/h) fueled the fires and hampered the efforts of 150 firefighters. Two other nearby fires threatened homes and businesses in the towns of Brigadoon, Baskerville, Millendon and Red Hill. The fires were contained by the 8th, but not before burning nearly 3,707 acres (1,500 hectares).


Madrid Smog
Smog over Madrid, Spain 7 February
Image Credit: Reuters

On February 8th, dense smog settled over Madrid, Spain, causing air pollution concerns for the capital city for several days. Smog warnings were issued when the nitrogen dioxide levels in the city rose above 5 times the legal limit of 200 micrograms per cubic meter, set by the European Union. A strong high pressure system over the Iberian Peninsula prevented the dispersion of air pollution and limited rainfall which can act as a natural air purifier. The heavy automobile traffic in the city also contributed to the problem. Such a high level of nitrogen dioxide can cause stress on vulnerable populations such as senior citizens and young children.

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Extreme Temperatures

A rare cold snap took place between February 3rd-4th across the northern Mexican state of Chihuahua. Temperatures dropped to 0°F (-18°C) in the border city of Ciudad Juarez. This is the lowest temperature recorded in the city since 1950. Six people were reported to have died due to the freezing temperatures. Power outages due to increased power demand closed factories and businesses across the state. Snow reported in the city closed the airport for several hours as officials did not have the infrastructure to handle the ankle deep snow. City shelters were filled to capacity as residents without electricity and heat searched for reprieve from the freezing temperatures. A zoo in the town of Aldama lost power, causing the failure of heating elements for the animals and 35 animals froze to death — 14 parrots, 13 serpents, five iguanas, two crocodiles and a capuchin monkey.

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Heavy rainfall and flooding

Sri Lankan Rainfall 1-6 Feb
Sri Lanka Rainfall 1-6 February
Image Credit: NASA

Between February 1st and 6th, heavy rainfall impacted northern Sri Lanka for six consecutive days, following flooding which hit the region during January. Authorities confirmed 11 deaths and another two missing. Flood waters inundated roads cutting off several towns to aid, and reports claim that 1.25 million people were directly affected by the floods. More than 320,000 people were displaced and forced to move into government refugee camps. The Anuradhapura and Polonnaurwa districts were the hardest hit, located northeast of the capital city Colombo. Over 90 percent of the country’s rice crops were threatened, which is a staple food for those who live in Sri Lanka. Sri Lanka cultivates 570,000 hectares (1.4 million acres) of rice paddies twice a year and another 100,000 hectares (250,000 acres) had recently been added in the northern and eastern provinces, the government says.


Victoria Flooding
Southeast Australia Flooding 8 February
Image Credit: NASA

The remnants of tropical cyclone Yasi quickly raced across Queensland and stalled out across the southeastern Australian state of Victoria, causing floods on February 4th-6th. Heavy rains impacted the region during January, and Yasi worsened the already soggy conditions. ABC Australia reported the worst flash floods occurred across northwestern Victoria. Melbourne, Australia’s second largest city, was also hard hit with flooding. A state of emergency was issued to keep people from entering the streets of the city on inflatable toys and rafts. Moisture from the storm interacted with a cold front pushing across Victoria to cause the heavy rains. Southeast of Melbourne, damage to potato, cauliflower, and broccoli farms was widespread. Up to 7 inches (175 mm) of rain fell in the city over the course of a single day and wind gusts of 80 mph (130 km/hr) were reported. The State Emergency Service said 84 people were rescued from cars that stalled in flooded streets and from inundated properties.

Warm temperatures during the first half of February caused the snow pack over the high terrain of Afghanistan to melt, leading to flooding in the western regions of the country. TOLOnews reported that hundreds of homes and thousands of acres of agricultural land were destroyed due to the run-off water. Six people were reported killed in western Herat province, and in Herat and Shindand provinces combined, at least 2,000 households were affected by the high waters. Regions of the Zerko Valley were the hardest hit, where farm lands became lakes. The floodwater could be beneficial in the longer term, providing nutrients and moisture to crop lands for the upcoming growing season.


Photo of La Paz, Bolivia Landslide
La Paz, Bolivia Landslide
Image Credit: AP

Heavy rains across Bolivia the last weekend of February caused landslides across several regions of the country. At least 45 people were reported to have been killed due to floods and mudslides, and another 10,000 people lost their homes. Particularly hard hit was the capital city of La Paz, where 2 inches (50.8 mm) of rain fell on the 25th and 26thnearly half the February monthly average. Much of the city is built upon steep mountainsides, and the deluge of water caused the mountainsides to weaken. A bridge collapse near the Kupini II area of La Paz killed five people in a bus. The bridge collapse prompted evacuations of the area before a 91 hectare piece of the mountain slide away, destroying 400 homes in the neighborhood. Fortunately, the evacuations prevented any further deaths in the city. The densely populated neighborhood of Valle de Las Flores was also threatened by weakened hillsides. According to media reports, the landslides were the worst to ever affect La Paz. The worst of the flooding occurred in the northern Amazon lowlands, where dozens of rural communities were cut off by rivers that had burst their banks. The Bolivian government blamed the unusualness of this year's rainy season on La Niña.

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Tropical Cyclones

Yasi Satellite Image
Tropical Cyclone Yasi
Image Credit: Australian BOM

Severe tropical cyclone Yasi made landfall in northern Queensland near Mission Beach on February 3rd. When the storm made landfall, it produced wind gusts estimated as high as 177 mph (285 km/hr) and a central minimum pressure of 929 mb. Rainfall totals were generally between 7.9-11.8 inches (200-300 mm), but localized higher amounts were reported — 18.5 inches (471 mm) in South Mission Beach, 18.2 inches (464 mm) in Hawkins Creek, 16.0 inches (407 mm) in Zattas, and 14.7 inches (373 mm) at Bulgun Creek. A storm tide of 16.4 feet (5 meters) was measured during the astronomical low tide which helped to limit inland inundation due to the storm. Estimates by Tropical Storm Risk, Inc. placed damages near 3.5 billion U.S. dollars, which made Yasi the second most costly tropical cyclone to ever affect Australia. Cyclone Tracy hit Darwin on Christmas Day in 1974 and cost approximately 3.6 billion U.S. dollars (adjusted to 2011) in damage. Yasi missed the highly populated cities along the coast, which also limited the amount of damage. Media reports claim that up to 90 percent of structures in the towns where the eye of the storm made landfall were damaged or destroyed.


Bingiza Satellite Image
Satellite Image of Cyclone Bingiza
Image Credit: NASA

On February 14th, Tropical Cyclone Bingiza made landfall near Saranambana, along Madagascar’s northeastern coast, with maximum sustained winds estimated at 115 miles per hour (185 km/hr), according to the U.S. Navy. This ranked Bingiza as a Category three tropical cyclone. The storm caused six deaths in Madagascar, destroyed 8,500 buildings, and left 15,000 people homeless. Bingiza traversed the rugged terrain of Madagascar and re-emerged over the Mozambique Channel between Africa and Madagascar on the 15th as a tropical depression. Late in the day on the 15th, Bingiza re-intensified to a tropical storm over the warm waters and made a second landfall along Madagascar’s southeastern coast. Across the entire country, 14 people were killed, 64 were injured, and another 11 reported missing.


Carlos Rainfall
Satellite Estimate of Carlos Rainfall
Image Credit: NASA

Tropical Cyclone Carlos formed off the northern Australian coast on February 14th, and remained stationary for three days over Australia's Northern Territory coastal region. On the 16th, 13.4 inches (340 mm) of rain fell in Darwin, breaking the 24-hour rainfall record for the city. The three day total precipitation (14th–16th) for the city was 26.96 inches (684.8 mm), also a record. The rains caused heavy flooding in Darwin, and the city tied the record rainfall for the month by the 17th. The city dam on the outskirts of Darwin was overtopped by rising water, leaving Darwinians to watch as belongings were swept away in the resulting floods. The Darwin airport was forced to close for two days because of the deluge of water. City residents were warned to watch out for snakes and crocodiles, as the animals were disturbed by the heavy rains. As Carlos moved off to the Southwest, it brought heavy rain and strong winds to the northern regions of Western Australia on the 18th through 22nd, forcing the suspension of petroleum mining projects. Floodwaters in the town of Carnarvon peaked at 23 feet (7 meters) above flood stage on the 19th, causing minor damage to buildings in the town. Although flooding was widespread, total damage caused by the storm appeared to be minimal.

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Severe winter weather

U.S. February 2nd Snow Cover
Central U.S. Snow Cover 2 February
Image Credit: NASA

A very large and strong winter storm hit the central and northeastern U.S. and southern Canada between February 1st and 3rd and was dubbed the 'Groundhog’s Day Blizzard of 2011'. Impacts were also felt from New Mexico northward to Wisconsin and eastward into Maine. Reports of snowfall over 20 inches (50.8 cm) were widespread. At one point, the storm stretched over 2,000 miles (3,200 km), and 22 states had snowfall accumulations greater than five inches (12.7 cm). Portions of southern Ontario, Canada, received 7.9 inches (20 cm) of snow. The storm also brought heavy amounts of freezing rain and ice to portions of the Ohio River Valley and Great Lakes, with some locations observing up to 1.0 inch of ice accumulations. The storm also brought strong winds and gusts as high as 70 mph (113 km/hr) were reported in Chicago. On the 2nd, an estimated 375,000 households in the U.S. and southern Canada were without power due to the snow, ice, and strong winds. Across the U.S., 6,300 flights were cancelled with 938 of those being at Chicago’s O’Hare International Airport. In the state of Missouri, all 250 miles of Interstate Highway 70 were closed. Highways and rail systems were also closed across much of Illinois. In Oklahoma, the Tulsa World newspaper was unable to publish because of the heavy snow — the first time in its 105-year history. Chicago observed 20.2 inches (51.3 cm) of snow for the event, which is the third largest snowfall accumulation ever recorded for the city. Media reports claim the combination of the heavy snowfall and the gusty winds made this the worst blizzard in Chicago’s history. The largest snow accumulation associated with the storm was in Antioch, Illinois, where 27 inches (68.6 cm) of snow was measured. The storm weakened somewhat as it moved into the Northeast on the 3rd, dropping around a foot (30.5 cm) of snow in New England. In total, at least 10 people died across the U.S. due to the storm.


Dallas Snowfall Accumulation 4 February
Texas Snow Accumulation 4 February
Image Credit: NWS

On February 4th, a winter storm moved across northern Texas, dropping four to six inches (10-15 cm) of snow over the Dallas, Texas metropolitan area. The average annual snowfall for the city is 2.6 inches (6.6 cm). The snow caused the cancellation of more than 300 flights at Dallas airports, as fans were arriving for Super Bowl XLV. Media reports claimed that hotels catering to the influx of sports fans handed out ski hats and scarves alongside the regionally iconic cowboy hat. As crews prepared the stadium for the game, chunks of ice fell, sending seven workers to the hospital. By the time the game was played on the 6th, conditions had warmed and most of the snow had melted. The National Football League (NFL) was impacted by several weather events this season. The first Monday night game of the season started with a delay due to thunderstorms in a New York City suburb and the Metrodome in Minneapolis, Minnesota collapsed due to heavy snow on the roof on December 12th.


Southern U.S. Snow Cover
Satellite Image of Southern U.S. Snow
Image Credit: NASA

On February 8th and 9th, a winter storm brought heavy snow to the south-central U.S., breaking many local snowfall records. This storm was on the heels of the ‘Groundhogs Day’ major snow storm. Snowfall totals in parts of Oklahoma, Kansas, and Arkansas topped 20 inches (50 cm). The 5.5 inches (14 cm) of snow in Tulsa, Oklahoma brought the seasonal snowfall total to 26 inches (60 cm), marking the snowiest winter on record for the city. Oklahoma City observed 6 inches (15 cm) of snow, making February 2011 its second snowiest month (18 inches) on record, behind March 1923. The back-to-back snow storms caused numerous roofs to collapse and there were at least 80 reports of storm-related injuries. Tulsa spent 2 million U.S. dollars on 68 pieces of snow removal equipment and 600 tons of salt to help clear roads. The Federal Emergency Management Agency (FEMA) declared a state of emergency in Oklahoma, making federal money available to reimburse municipalities for snow-related costs. In addition to the heavy snow, very cold temperatures moved into the region. On the 10th, the temperature in Nowata, Oklahoma dropped to -31 degrees F (-35 degrees C), breaking the all-time coldest temperature record for the state of Oklahoma.


Korean Snowstorm
Image of Korean Snow 14 February
Image Credit: NASA

Between February 11th and 14th, a strong storm grazed the eastern coast of the Korean Peninsula, dropping over 3 feet (91 cm) of snow. Samcheok, South Korea measured 39 inches of snow (100 cm) during the course of the storm, the largest storm accumulation measured in South Korea since records began in 1911. It was reported that one rural town received 31.5 inches (80 cm) of snow in 24 hours — potentially a new South Korean record for snowfall in a single day. The South Korean military sent 12,000 soldiers to assist stranded motorists and trapped residents in the region, and officials in the Gangwon province mobilized 22,600 volunteers and 1,750 snow plows to clear highways. Property damages were estimated at 4.3 million U.S. dollars. There were 80 flights canceled and 40 delayed at Gimhae International Airport and roads were closed in and around the nearby port city of Busan. Officials said that 146 remote households in the Gangwon province were unreachable due to the deep snow. To the west, Seoul was spared the worst of the snow, but the Han River froze over for the first time in years, according to the BBC. The heavy snow arrived on the heels of South Korea’s coolest January since the 1960s.

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National Snow & Ice

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.

The weather pattern during the first half of February brought two large snow storms to the central parts of the U.S., but a pattern change around the middle of the month shifted the storm track to the West coast and along the northern tier of the country. The snow broke many daily, monthly, and seasonal snowfall records at many locations within these regions. See our records page for additonal information. By the end of the month, most high elevation locations in the West had snow pack levels which were near- to above normal, with the exception of the southern Rockies and parts of the Cascade Mountains. February provided a reprieve from the snow for the Southeast and much of the Eastern Seaboard. Even though snowfall was widespread during February, a significant portion of the county continued to suffer from an ongoing drought. See the U.S. drought monitor for more information. According to data from the Rutgers Global Snow Lab, a NOAA supported facility, during the month, the Southeast, Mid-Atlantic, the Central Plains, and parts of the interior West had below average snow cover during the month. Conversely, the Great Lakes, the Northern Plains, and the high elevations of the West had above average snow cover.

Based upon satellite analysis, the contiguous U.S. had a February average snow cover extent 251,000 square miles (0.65 million square km) above the long-term average of 1.2 million square miles (3.1 million square km), ranking as the ninth largest February snow cover extent in the 45-year period of record. At the beginning of the month, 52.2 percent of the country was under snow cover — the Northeast, Great Lakes, the Central and Northern Plains, parts of the Southern Plains, and the high terrain of the West. By the end of the month, 49.5 percent of the U.S. was snow covered, the Northeast, Great Lakes, the Northern Plains, the high elevations of the West, and the Great Basin. The maximum monthly snow cover extent occurred on February 10th, when 65 percent of the U.S. was snow covered — all states except Florida had snow on the ground.

Water Vapor Satellite Image of Groundhog Day Storm
Water Vapor Imagery of 1 February Storm
Source: NWS

On February 1st–3rd a large and powerful winter storm, dubbed the ‘Groundhog Day Blizzard’, hit the central and northern regions of the United States from New Mexico northward to Wisconsin, and eastward to New England. The storm stretched for thousands of miles, leaving behind at least five inches (12.7 cm) of snow in 22 states. The multi-faceted storm also brought an inch of ice to portions of the Ohio River Valley. Winds gusting upwards of 70 mph (113 km/hr) created widespread blizzard conditions, and snow drifts were reported as high as 10 feet (3 meters). Numerous highways were forced to close and thousands of flights were cancelled nationwide. The storm began across the Southern Plains on the 1st, where it dropped 1 to 2 feet (30.5 cm – 61 cm) of snow across Texas, Oklahoma, and Missouri. The largest snow amounts occurred across northern Illinois and southern Wisconsin on the 2nd. At Chicago, O’Hare Airport, the 20.2 inches (51.3 cm) of snow was the third largest storm accumulation ever recorded for the city. Racine, Wisconsin observed 26 inches (66.0 cm) of snow during the event, breaking the city’s 48-hour and 72-hour snowfall records. Snowfall records for Chicago date back to 1886 and to 1896 for Racine. The storm then moved off into the Northeast on the 3rd, where it left behind a foot of snow. Buildings in Connecticut and Massachusetts collapsed under the weight of the new snow, in addition to snow from previous storms. According to scientists at the CPC, the track of the storm was likely influenced by the ongoing La Niña across the equatorial Pacific. Please see Global Hazards for additional information on this storm.

Oklahoma Temperature Records 10 Feb
10 February Oklahoma Temperature Records
Source: NWS

On the 8th and 9th of the month, another powerful winter storm hit the Southern Plains states, leaving behind 20 inches (50.8 cm) or more of snow in Oklahoma, Arkansas, and Kansas. As the storm moved off to the east, it also brought snowfall to northern parts of the Gulf Coast States, with up to six inches (15.2 cm) of snow reported in parts of Mississippi and Alabama. Tulsa, Oklahoma, received 5.5 inches (14 cm) of snow for the event, helping push the city over its seasonal snowfall record, with 26.1 total inches (10.3 cm) accumulating since December. Records for Tulsa date back to 1893. Oklahoma, City received six inches (15.2 cm) of snow during the event, putting the monthly total to 18.9 inches (48 cm), marking the second snowiest month on record for Oklahoma City, behind March 1923 when 20.7 inches (52.6 cm) of snow fell. Spavinaw, Oklahoma received 27 inches (68.6 cm) of snow over a 24-hour period on the 8th and 9th, breaking the 24-hour snowfall record for the state. Also associated with the storm were very cold temperatures, once the associated cold front pass through. On the 10th, the temperature in Nowata, Oklahoma dropped to -31 degrees F (-35 degrees C), breaking the all-time coldest temperature record for the state of Oklahoma. Please see the Febuary Global Hazards report for more information on this storm.

22 febuary minnesota Snowfall
22 February Minnesota Snow Accumulations
Source: NWS

On February 20th and 21st, a snow storm moved through the Northern Plains and Western Great Lakes leaving behind up to 20 inches (50.8 cm) of snow. Minneapolis, Minnesota received 13.8 inches (35.1 cm) for the event, the largest February storm accumulation to affect the city on record, and the first time over a foot of snow has fallen in the city during the month of February. The previous record was 11.2 inches (28.4 cm) in February 2004. The entire winter season for Minneapolis has been particularly snowy, with snow during the December through February period measuring 66.7 inches (169.4 cm), the second snowiest on record, behind the same period in 1966-1967 when 71.7 inches (182.1 cm) of snow fell. Heavy snow during February is uncommon in the region, with the heaviest snows tending to occur earlier or later in the winter season. The copious amounts of snow this winter across the Northern Plains will likely cause issues this spring when it begins to melt into rivers, potentially causing flooding. According to NOAA scientist, there is an above average chance for record flooding in the region.

27 Feb Southern California Snow
27 February Southern California Snow Cover
Source: NWS

A strong and unseasonably cold storm system hit the West coast on February 24th through 27th, bringing a mixed bag of precipitation from Seattle to the suburbs of Los Angeles. As the cold front associated with the storm moved through it brought heavy rain and strong winds. Once it passed, cold air and Pacific moisture filtered into the region. Snow levels dropped to sea level, allowing snow to fall in downtown Seattle as well as the San Francisco airport, where a trace was measured. The last measureable snowfall greater than a trace in San Francisco was in 1976. In the Cascades and Sierra Nevada mountain ranges, snowfall totals reached up to four feet (122 cm) where the temperatures remained cool enough to support snow during the entire event. Further to the south, snow fell in the mountains around Los Angeles and San Diego, with snow levels dropping to around 1,000 feet (305 m).

Tornadoes

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.


According to data from the Storm Prediction Center (SPC), the preliminary tornado count for February 2011 across the U.S. was 59, marking an above-average February in terms of the number of tornadoes. This preliminary count ranks as the fourth busiest February on record. The final monthly tornado count is typically less than the preliminary count, and the final count will likely rank among the top ten busiest Februaries. Tornado activity was significantly higher during February 2011 compared to February 2010, when only one tornado was confirmed in the United States. Most of the tornado activity was confined to the southern and southeastern U.S., which is typical this time of year as cold fronts moving from the Canadian border interact with relatively warmer and moist air from the Gulf of Mexico. The majority of the tornadoes (55) occurred in two separate outbreaks, one on the 24th and one on the 27th and 28th.

A significant severe weather outbreak occurred across the Tennessee River Valley on February 24th. According to preliminary counts, there were 25 tornadoes and 262 severe wind reports. The strong storm system also brought heavy rains to the area, where 3 to 5 inches (76-127 mm) of rain fell in western Tennessee. The strongest tornado of the outbreak occurred near Parsons, Tennessee. The EF-2 tornado was on the ground for 12 miles (19.3 km) with a maximum width of 400 yards (366 m). Winds with the tornado were estimated near 120 mph (193 km/hr). There were no injuries or fatalities associated with the tornado, but damages to homes and businesses were estimated at 1.285 million U.S. dollars.

Another severe weather outbreak occurred on the 27th and 28th of the month when a strong cold front moved through the Midwest and Southeast. Over the two days, there were 30 preliminary tornado reports, 308 strong wind reports, and 88 hail reports stretching from Kansas to Georgia. The strongest tornado of the outbreak, anEF-3 occurred near Eminence, Kentucky in the early morning hours of the 28th. The tornado was on the ground for 2.3 miles (3.7 km) and had estimated winds of 140 mph (225 km/hr). The first tornado related fatality of 2011 was reported in Franklin County, Tennessee, near the town of Tullahoma. The EF-2 tornado had winds estimated at 125 mph (201 km/hr) and was on the ground for 11 miles (17.7 km), uprooting thousands of trees in its path. Four other people were also injured in the storm.

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Hurricanes & Tropical Storms

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.


Note: This report catalogs recent tropical cyclones and places each basin's tropical cyclone activity in a climate-scale context. It is not updated in real time. Users seeking real time status and forecasts of tropical cyclones should visit The National Hurricane Center.

South Pacific Basin

Zaka
Tropical Storm Zaka Satellite Image
Zaka Track
Tropical Storm Zaka Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Zaka
Cyclogenesis Date 02/06
Cyclolysis Date 02/07
Highest Saffir-Simpson Category TS
Maximum 6-hr Sustained Wind 52 mph (45 kt or 83 km/h)
Min Pressure 985 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) .8063 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths 0
*The (ACE) Index calculations are based on preliminary data.

Atu
Tropical Storm Atu Satellite Image
Atu Track
Tropical Storm Atu Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Atu
Cyclogenesis Date 02/18
Cyclolysis Date 02/23
Highest Saffir-Simpson Category Cat 4
Maximum 6-hr Sustained Wind 132 mph (115 kt or 213 km/h)
Min Pressure 940 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 14.0375 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths 0
*The (ACE) Index calculations are based on preliminary data.


South Indian Basin

Bingiza
Tropical Storm Bingiza Satellite Image
Bingiza Track
Tropical Storm Bingiza Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Bingiza
Cyclogenesis Date 02/09
Cyclolysis Date 02/17
Highest Saffir-Simpson Category Cat 3
Maximum 6-hr Sustained Wind 115 mph (100 kt or 185 km/h)
Min Pressure 953 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 11.3731 x 104
Landfall Information (date, location and sustained winds) 02/14 – northeastern Madagascar (86 kt or 160 km/h)
Deaths 0
*The (ACE) Index calculations are based on preliminary data.


Australian Basin

carlos
Tropical Storm Carlos Satellite Image


Australian Scale Color Legend for Track Map from Unisys
Australian Scale Color Legend
Carlos Track
Tropical Storm Carlos Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Carlos
Cyclogenesis Date 02/15
Cyclolysis Date 02/26
Highest Australian Category Cat 1
Maximum Gust 148 km/h
Highest Saffir-Simpson Category TS
Maximum 6-hr Sustained Wind 75 mph (65 kt or 120 km/h)
Min Pressure 968 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 6.5963 x 104
Landfall Information (date, location and sustained winds) 02/16 – northeastern Australia (35 kt or 65 km/h)
Deaths N/A
*The (ACE) Index calculations are based on preliminary data.

Dianne
Tropical Storm Dianne Satellite Image


Australian Scale Color Legend for Track Map from Unisys
Australian Scale Color Legend
Dianne Track
Tropical Storm Dianne Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Dianne
Cyclogenesis Date 02/16
Cyclolysis Date 02/22
Highest Australian Category Cat 3
Maximum Gust 194 km/h
Highest Saffir-Simpson Category Cat 2
Maximum 6-hr Sustained Wind 98 mph (85 kt or 157 km/h)
Min Pressure 962 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 9.1006 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths N/A
*The (ACE) Index calculations are based on preliminary data.

Yasi
Tropical Storm Yasi Satellite Image


Australian Scale Color Legend for Track Map from Unisys
Australian Scale Color Legend
Yasi Track
Tropical Storm Yasi Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Yasi
Cyclogenesis Date 01/30
Cyclolysis Date 02/03
Highest Australian Category Cat 5
Maximum Gust 306 km/h
Highest Saffir-Simpson Category Cat 4
Maximum 6-hr Sustained Wind 155 mph (135 kt or 250 km/h)
Min Pressure 922 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 15.0594 x 104
Landfall Information (date, location and sustained winds) 02/3 - Queensland, Australia (125 kt or 232 km/h)
Deaths 1
*The (ACE) Index calculations are based on preliminary data.

Drought

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.

Issued 15 March 2011
Contents Of This Report:
Map showing Palmer Z Index

National Drought Overview

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Detailed Drought Discussion

Overview

February 2011 ranked near the middle of the 117-year historical distribution (41st driest and 51st coolest, based on data back to 1895) when weather conditions are averaged across the country. But this reflected regional extremes (monthly precipitation and temperature) which resulted from the changing weekly regional patterns of precipitation (weeks 1, 2, 3, 4) and temperature (weeks 1, 2, 3, 4) anomalies throughout the month. Beneficial precipitation fell across parts of the drought areas in the Southeast early in the month and Ohio Valley/Midwest later in the month. But precipitation totals for the entire month were drier than normal over most of the drought and abnormally dry areas as well as parts of the north central states and Far West. The drought area contracted in the Ohio Valley, but abnormally dry to extreme drought conditions expanded across parts of the Southern Plains to Southeast, and moderate to severe drought expanded across parts of the Southwest. Severe drought slightly contracted but moderate drought expanded in Hawaii, especially on the Big Island. About 28 percent of the contiguous U.S. was experiencing moderate to extreme drought at the end of February, reflecting a steady rise in drought extent since last summer when the percent area dropped to the lowest value in the USDM 11-year record.

U.S. Drought Monitor map from March 1, 2011
The U.S. Drought Monitor drought map valid March 1, 2011.

February 2011 had a very active weather patternweather pattern over the contiguous United States. A high amplitude circulation (one with many troughs and ridges and low pressure sytems) dominated during the first part of the month, resulting in winter storm sytems moving across many parts of the country. Significant troughing occurred in the West early in the month, sending very cold Canadian air plunging into the Lower 48 States. The cold air followed a strong low pressure system which increased national snow cover to its greatest February 2011 extent of about 65 percent of the country by the 10th. February 2011 snow cover was the 9th largest February extent for the contiguous U.S. and 8th largest for North America in the 45-year satellite snow cover extent record.

The circulation pattern switched to a more zonal flow later in the month, with the storm track more along the northern states. Temperatures moderated when the circulation pattern flattened at mid-month, but the month ended with surges of cold air behind strong cold fronts which brought tornado outbreaks on the 24th and 27th-28th. There were 59 preliminary tornado reports during February 2011, ranking the month in the top ten busiest Februaries. The Southeast drought areas received beneficial preciptation early in the month, but the shift of the storm track further north later in the month left the South dry while bringing relief to the Midwest and Ohio Valley drought areas. February ended with moderate to extreme drought covering 23 percent of the U.S., about 3 percent higher than at the end of January. Wildfire activity was high during the month, particularly across the South and Southeast drought areas, with a record high February number of wildfires and second highest for acres burned. The mid-month circulation shift was accompanied by a surge of winter storms into the West, whose rain and snow ended a one and a half month lull in precipitation. The month started with about half (52.2 percent) of the country covered in snow and ended with about half (49.5 percent) snowcovered.

The circulation pattern flip-flop resulted in nationally-averaged temperature and precipitation ranks in the middle of the 117-year historical distribution (51st coolest and 41st driest February). But extremes occurred on the state level, with Wyoming having the 15th coolest February, Virginia the 21st warmest, Louisiana and Mississippi 8th driest, and Ohio (5th wettest), South Dakota (6th wettest), and Indiana (10th wettest) each in the top ten wettest category.

Cold fronts and low pressure systems moving in the storm track flow are influenced by the broadscale atmospheric circulation. Two such large-scale atmospheric circulation patterns were dominant during February. The first was a weakening La Niña, which is the phenomenon created by cooler-than-average sea surface temperatures in the eastern tropical Pacific Ocean. At this time of year, La Niña is typically associated with dry conditions in the Southwest, Southeast, and southern Plains, a wet signal along the Ohio Valley and in the northern tier states, and warmer-than-normal temperatures across most of the country, especially in the Southwest. The second atmospheric circulation index was the Pacific/North American (PNA) pattern, which transitioned from a weak positive or neutral phase during the first part of February to a negative PNA during the last half of the month. A negative PNA this time of year is typically associated with warmer-than-normal temperatures over the southeast third of the U.S., colder-than-normal temperatures in the Northwest, and wetter-than-normal conditions in the Pacific Nothwest and from the Ohio Valley northward. The pattern of observed temperature anomalies for February 2011 generally matched the La Niña and negative PNA in the East. In the West, the negative PNA pattern dominated, except the cold anomalies encompassed a larger area than normally associated with a negative PNA. This is associated with strong troughing in the West and ridging in the Southeast in the monthly averaged circulation. The observed precipitation pattern in February east of the Rockies largely matched the pattern expected from La Niña and a negative PNA, especially in the Southwest.

By the end of the month, the core drought areas in the U.S. included:


Palmer Drought Index

Palmer Z Index map Palmer Hydrological Drought Index map

The Palmer drought indices measure the balance between moisture demand (evapotranspiration driven by temperature) and moisture supply (precipitation). The Palmer Z Index depicts moisture conditions for the current month, while the Palmer Hydrological Drought Index (PHDI) and Palmer Drought Severity Index (PDSI) depict the current month's cumulative moisture conditions integrated over the last several months. As seen on the Palmer Z Index map, low precipitation resulted in dry conditions for February 2011 in a band from the Mid-Atlantic States to Texas, the southern half of Florida, parts of the western Great Lakes, and parts of the Northwest and Southwest. Wet conditions for February are evident on the Z Index map from much of the Northeast to Midwest, and across parts of the northern Plains and West. Near-normal conditions occurred in a band across the coastal Southeast. Compared with the January 2011 PHDI map, the February 2011 PHDI map indicates that drought conditions intensified in parts of the Gulf Coast States; drought conditions contracted in the Ohio Valley; and moist conditions persisted across much of the Upper Midwest, Northern Plains, and parts of the West. The February 2011 PHDI map also reflects the long-term nature of the drought conditions. The Z Index and PHDI maps in combination show that the dryness in the Southeast to Southwest is both a short-term and long-term phenomenon; that the dryness in the western Great Lakes is a short-term phenomenon; that the wetness in the Ohio Valley is also a short-term phenomenon; and that the wetness in the northern Plains and parts of the Rockies is both a short-term and long-term phenomenon.


Standardized Precipitation Index

1-month Standardized Precipitation Index 2-month Standardized Precipitation Index 3-month Standardized Precipitation Index

The Standardized Precipitation Index (SPI) measures moisture supply. The SPI maps here show the spatial extent of anomalously wet and dry areas at time scales ranging from 1 month to 24 months. Dryness is evident across parts of the Southwest, Deep South, and Mid-Atlantic States from 1 month to 9 months to 12 months, and across much of this area and the Southern Plains at 3 to 6 months. Dryness in parts of the Great Lakes occurs at 1 month to about 6 months. Parts of the Northwest were dry at the 1-month time scale, and much of the West was dry at 2 months, but large areas of wetness show up across the West at the 3- to 12-month time scales. Much of the Northeast to central Midwest was wet at the 1-month time scale, with parts of this area wet at 2 months. The Northeast is wet from 6 to 24 months. The Northern Rockies and Northern Plains are persistently wet at most time scales, especially the 3- to 24-month time scales. Dryness is rare at 24 months.


6-month Standardized Precipitation Index 12-month Standardized Precipitation Index 24-month Standardized Precipitation Index

Agricultural Indices

Leaky Bucket model soil moisture percentiles
Leaky Bucket model soil moisture percentiles
Maximum number of consecutive dry days
Maximum number of consecutive dry days

Abnormal dryness and drought were evident in several indicators. There were hardly any days with precipitation across the Southern Plains, Southwest, Great Basin, and parts of interior Northwest, as well as southern Florida and the northwestern Great Lakes. This resulted in long runs of consecutive dry days in these areas. Long dry runs (2 weeks or longer) also occurred across much of the Southeast. The dryness is also reflected in low total precipitation amounts and below-normal precipitation. On the other hand, it rained or snowed half or more of the days of the month along the coastal Pacific Northwest and parts of the Northern Rockies and eastern Great Lakes. During the winter cold season, vegetation goes dormant across much of the country. But soil moisture, as monitored by several models (NOAA Climate Prediction Center [CPC] anomalies and percentiles, Leaky Bucket, NLDAS [North American Land Data Assimilation System] top soil layer and total soil layer, VIC [University of Washington Variable Infiltration Capacity macroscale hydrologic model] percentiles), continued very dry from the Mid-Atlantic States to the Lower Mississippi Valley, with areas of dryness across the Southwest to Southern and Central High Plains, lingering dryness in parts of the Ohio Valley and southern Great Lakes, and a hint of dryness in parts of Alaska and Hawaii. Satellite monitoring of vegetation health (Vegetation Drought Response Index [VegDRI], Vegetation Health Index [VHI]) indicated stress on vegetation in parts of the Southwest, Southern to Central Plains, Southeast, and Ohio Valley.


Hydrological Indices

Well monitoring stations (real-time network, climate response network, total active network) in the drought-stressed areas continued to show low groundwater levels. Streamflow (observed and modeled [CPC anomalies and percentiles, VIC 1-, 2-, and 3-month runoff percentiles]) was below average for the month across much of the Mid-Atlantic to Gulf Coast States and parts of the Southwest, Southern Plains, Ohio Valley, northwestern Great Lakes, coastal Pacific Northwest, and Hawaii.


USGS streamflow percentiles
USGS streamflow percentiles
USDA mountain snowpack
USDA mountain snowpack

Regional Discussion

February had a mixed temperature and precipitation pattern across Alaska, although most of the state was wetter than normal with February 2011 ranking as the 10th wettest February in the 1918-present record. Dryness in the southern portions of the state is reflected in the February precipitation pattern and mountain snowpack and SNOTEL station network snow water equivalent. The March 1st USDM map had a sixth of the state in the abnormally dry category, which was about half compared to last month and reflected February's above-normal precipitation. However, long-term deficits still remained at several stations at longer time scales (2, 3, 6, 12, 24, 36 months).

Most of Puerto Rico was drier than normal during February. This continued a trend which has been going on for the last 2 to 3 months. The dryness is not as widespread at longer time scales (last 6 months). Streamflow for Puerto Rico was near normal and the island remained drought free on the March 1st USDM map.

The rainfall pattern across the Hawaiian Islands was mixed during February. The area under severe (D2) drought shrank this month, compared to the end of January, but the area under moderate drought (D1) expanded, especially on the Big Island. Long-term rainfall deficits continued at many stations at several time scales, especially the longer time scales (last 2, 3, 6, 12, 24, 36 months), and February streamflow continued below normal on Maui and the Big Island.

State precipitation ranks, December 2010-February 2011 Virginia statewide precipitation, January-February, 1895-2011

On a statewide basis, February 2011 was drier than normal for many states in the Southwest, Southern Plains, Southeast, and Mid-Atlantic regions. Two states (Louisiana and Mississippi) had the 8th driest February in the 1895-present record. Dryness is evident for much of the last 12 months. The year-to-date (January-February 2011) was drier than normal for the southern half of the country and much of the West, with Virginia ranking 2nd driest, New Mexico 4th driest, and North Carolina 7th driest. This winter (December 2010-February 2011) was especially dry from the Mid-Atlantic to Southern Plains, with 11 states much drier than normal and 8 of those ranking in the top 10 driest category. Seven states in the Southeast ranked in the top 10 driest category for September 2010-February 2011, and 5 of them were in the top 10 driest category for the last 12 months (March 2010-February 2011).

Arkansas climate division 8 (South Central) precipitation, March 2010-February, 1895-2011 North Carolina division 3 (Northern Piedmont) precipitation, January-February, 1895-2011

Record dryness occurred for several climate divisions for the last several months:

Year-to-date (January-February):

Winter (December-February):

Last 6 months (September-February):

Last 12 months (March-February):


The record dry March 2010-February 2011 followed a record wet March 2009-February 2010 in Arkansas climate divisions 8 and 9. Nine or 10 of the last 12 years had a very dry start (January-February) to the year in the piedmont areas of North Carolina (climate division 3) and Virginia (climate division 3). This is true on a statewide basis for these 2 states (North Carolina, Virginia) and on a regionwide basis for the Southeast region.

Percent area of the Western U.S. in moderate to extreme drought, based on the Palmer Drought Index
Percent area of the Western U.S. in moderate to extreme drought, January 1900-February 2011, based on the Palmer Drought Index.

The precipitation pattern over the West was mixed in February, with some areas wetter than normal and others drier than normal. On the whole, the western regions averaged near normal for the month. The February precipitation was not enough to overcome the dryness of January, with 2-month (January-February 2011) precipitation ranks still below normal for most western states. But heavy precipitation earlier in the season resulted in wetter overall conditions for winter (December 2010-February 2011) and the last 6 months (September 2010-February 2011). Water-year-to-date (October 2010-February 2011) precipitation was near normal in the Northwest, much below normal in the Southwest, and above normal in between. A similar pattern can be found in the mountain snowpack, snow water equivalent percentiles for SNOTEL stations, and snow water equivalent percent of normal for SNOTEL basins. An analysis of early data by the USDA indicated that reservoir levels were, on average, below normal from New Mexico, across the Interior Basin states, to Oregon, and near to above normal in Washington and Arizona and the Rocky Mountain states. According to the USDM, 15 percent of the West was experiencing moderate to severe drought at the end of February, slightly more than January, while the Palmer Drought Index statistic was about 9 percent, a slight drop compared to last month.

A more detailed drought discussion, provided by the NOAA Regional Climate Centers and others, can be found below.

As noted by the Southeast Regional Climate Center, mean precipitation for the Southeast region was slightly below normal in February, although there was much local variability. There were two relatively narrow corridors of above normal precipitation (125 to 150 percent), one that cut across the eastern Panhandle of Florida and one that stretched across southern Alabama, central Georgia, and eastern portions of the Carolinas. Much of this precipitation was tied to a series of storms that crossed the region on the 4th and 5th of the month. The driest locations (less than 25 percent of normal) were found in the southern half of Florida with some locations recording less than 5 percent of normal precipitation for the month. Most notably, Key West, Florida recorded only 0.01 inch (0.25 mm) of precipitation for the month, making it the second driest February in a record extending back to 1871. Elsewhere across the Southeast, monthly precipitation was generally between 50 and 75 percent of normal.

Mean temperatures were above normal across the Southeast in February. Mean temperatures were near normal across Puerto Rico, while the U.S. Virgin Islands experienced their fourth consecutive month of below normal temperatures. The cold weather that dominated the region in December and January continued into early February, particularly across parts of Alabama and Florida. However, temperatures rebounded significantly during the second half of the month as the Arctic Oscillation transitioned to a positive phase and more southerly and westerly winds became established over the Southeast. Despite a return to warm temperatures in February, mean temperatures during meteorological winter (December-February) ranked among the top 5 coldest in many locations across the region.

The lack of precipitation in February resulted in the emergence of severe (D2) and extreme (D3) drought conditions across the northern half of Alabama and southeastern Florida, respectively. However, the beneficial rains through portions of central Georgia and South Carolina resulted in a reduction from severe drought to moderate drought (D1) conditions in those areas. The warm temperatures near the end of the month caused many of the peach and blueberry crops to bloom across Georgia, making them especially vulnerable to a killing frost. According to the Georgia State Climate Office, a killing frost could have an economic impact of over $150 million to the industry. In addition to the warm temperatures, a combination of high winds, dry soils, ample leaf litter, and low relative humidity created ideal conditions for wildfires across much of the Southeast. In North Carolina, the Division of Forest Services reported over 12,000 fires across the state in February and more than 1,700 acres burned.

As explained by the Southern Regional Climate Center, with the exception of central and northern Arkansas, northern Tennessee and northeastern Oklahoma, the month of February was a dry month for the Southern region. The driest areas of the region included much of southern and southwestern Texas, where most stations received less than a quarter of the monthly normal precipitation total. In central Louisiana and southern Mississippi, the majority of stations reported precipitation totals that ranged between 25 and 50 percent of normal. Similar conditions were also observed throughout parts of central Texas and northwestern Oklahoma. The wettest area of the region included much of north central Arkansas where stations reported between 150 and 400 percent of normal precipitation. On February 9-10, 2011, many areas of Oklahoma received heavy snowfall accumulations. Accumulations varied from a few inches to over two feet in the northeastern portions of the state.

January average temperatures in the Southern region varied spatially from west to east. In the northwestern areas of the region, temperatures were generally 2 to 6 degrees F (1.11 to 3.33 degrees C) below the monthly normal. In Tennessee and Mississippi, however, temperatures averaged between 2 to 6 degrees F (1.11 to 3.33 degrees C) above the monthly normal. All state value temperature rankings fell within the two middle quartiles of the normal distribution as based on the 1895-2011 period of record.

Drier than normal conditions throughout most of the Southern region led to an expansion of drought in many areas. Most notably, there was an expansion of extreme drought in central and northern Louisiana and in eastern Texas. Southwestern Texas also experienced a slight expansion of extreme drought. On February 1, 2011, only 6.59 percent of the Southern region was experiencing extreme drought. One month later, on March 1, 2011, that number has increased to 10.76 percent. In Mississippi, the entire state was classified in moderate drought or worse. In fact, almost three quarters of the Southern region was in moderate drought or worse, compared to 58.97 percent of the region the previous month.

As summarized by the Midwest Regional Climate Center, Midwest February precipitation totals included pockets of below normal precipitation but also large areas exceeding 200 percent of normal. The below normal areas were extreme eastern Kentucky, southwestern Iowa, and the northern quarter of the region. The driest area was the upper Midwest were totals were less than 50 percent of normal. Snowfall totals were also quite variable in February. Below normal snowfall totals, as much as 50 percent below normal, occurred in southern Indiana, southern Ohio, and eastern Kentucky as well as across the upper Midwest. Snowfall totals were above normal with totals exceeding 200 percent of normal over swaths from southern Minnesota to southern Michigan and from Missouri to northern Ohio. Totals approached 700 percent of normal in southwest Missouri. Monthly records for snowfall were set in Chicago, Illinois, Galesburg, Illinois, Lansing, Michigan, and Flint, Michigan. Almost 900 daily snowfall records were set across the Midwest during the month. Winter season snowfall totals were above normal for nearly all of the Midwest. Slightly below normal totals fell in northern Michigan while totals exceeded 200 percent of normal in parts of the other eight Midwest states. More than 2900 daily snowfall records occurred during the three-month winter season. Winter season snowfall records were set in Peoria, Illinois and Rochester, Minnesota.

February temperatures varied in both time and space. The second week of the month was cold and the third week warm across the region. Weeks one and four varied spatially giving a mix of temperature departures for the month. Winter temperatures were near normal in northern Michigan and Wisconsin and below normal across most of the other Midwest states. February was the only winter month to report above normal temperatures for parts of the Midwest.

As noted by the Northeast Regional Climate Center, on average, the Northeast saw 119 percent of the normal precipitation amount, or 3.22 inches (81.8 mm). The three southernmost states were drier than normal with departures of 88 percent in West Virginia, 75 percent in Maryland, and 58 percent in Delaware. It was the 17th driest February in 117 years in Delaware. The states with above normal precipitation had departures that ranged from 104 percent in New Jersey to 143 percent in Pennsylvania, where it was the 17th wettest February since 1895. Precipitation totals for the region for climatological winter were exactly normal. The range of departures among the states was 68 percent of normal in Delaware to 122 percent in Maine. It was the 10th driest winter in Delaware and the 16th driest in Maryland. Drier than normal conditions in the southern part of the region have led to drought concerns there. The March 1, 2011 U.S. Drought Monitor indicated that parts of West Virginia, Maryland, Delaware and Pennsylvania were abnormally dry, while extreme eastern West Virginia was in moderately drought (D1). In addition, small areas in northern New York, Vermont, and New Hampshire were abnormally dry.

Temperatures in the Northeast averaged just below normal in February. The region's average of 25.6 degrees F (-3.6 degrees C) was -0.8 degrees F (-0.4 degrees C) below normal. It was the coolest February since 2007. The temperature average for the winter of 2010-2011 (December - February) was 24.2 degrees F (-4.3 degrees C), which was 2.0 degrees F (1.1 degrees C) below normal.

As explained by the High Plains Regional Climate Center, several storm systems affected the High Plains region this month. Overall, South Dakota, eastern Kansas, and pockets of both Colorado and Wyoming had precipitation which was above normal. The rest of the region had either near or below normal precipitation. A strong system brought extreme cold and snow to the region at the beginning of the month. Another round of snow hit the eastern portion of the region on February 8th-9th. The heaviest snow fell in eastern Kansas where up to 16 inches (41 cm) was reported. A mid-month warm-up allowed for much of the snow cover across the region to melt, however the snow cover quickly built up again. Later in the month a storm system moved through the region bringing thunderstorms, ice, and snow. On the 21st, thunderstorms occurred in eastern Nebraska while just to the north, ice accumulations up to a quarter inch were reported. Meanwhile, heavy snow fell across South Dakota, where over a foot (30 cm) of snow was reported in many locations. On February 24th another snow storm hit the region. Heavy snows of up to a foot (30 cm) were again reported in southwestern South Dakota and up to 5-9 inches (13-23 cm) were reported in Kansas and Nebraska. Also, in Kansas and Nebraska, much of the snow fell in a short amount of time and snowfall rates of 2 inches/hour (5 cm/hour) were reported.

The heavy snow this month not only led to new February records but also new winter (December-February) records. Bonner Springs, Kansas, which is just outside of Kansas City, recorded its snowiest February on record with 17.5 inches (44 cm) of snowfall (period of record 1938-2011). The old record was set in 1978 with 17.0 inches (43 cm). Aberdeen, South Dakota had its 4th snowiest February with 21.0 inches (53 cm) and its snowiest winter with 61.2 inches (155 cm) of snow (period of record 1893-2011). This beat the longstanding record of 57.0 inches (145 cm) which was set in 1915.

Meanwhile, North Dakota was on the dry side this month. Fargo, North Dakota received only 0.08 inch (2 mm) of liquid equivalent precipitation which was the 6th driest February on record and Grand Forks, North Dakota received only 0.04 inch (1 mm) of liquid equivalent precipitation which was the 4th driest February on record. The dry conditions this month did not stop the concern over flooding along the Red River or flood preparations. According to the North Dakota State Climate Office, Fargo had already filled 1.5 million sand bags and the North Dakota National Guard began training sessions to help prepare for the potential flooding.

February 2011 was a month of temperature extremes in the High Plains Region. The lowest temperatures of the month were, for the most part, observed at the beginning of the month. An arctic air mass settled into the Region and many daily low temperature records were set. Dangerous wind chills were also experienced throughout the Region. There was a warm-up mid month and daily high temperature records were broken in parts of Colorado, Kansas, Nebraska, and South Dakota but the month ended on the chilly side as cold air quickly moved back into the Region. Overall, February average temperatures were 2-6 degrees F (1.1-3.3 degrees C) below normal for most of the Region. The cold weather allowed many locations to break into the top 20 coldest Februaries on record. In addition, locations in Wyoming and the panhandle of Nebraska had average monthly temperatures which ranked in the top 10 coldest Februaries on record. Sunshine 3NE, Wyoming, which is located in the northwest part of the state, had its 2nd coldest February on record with an average temperature of 15.0 degrees F (-9.4 degrees C). The record of 11.0 degrees F (-11.7 degrees C) was recorded in 1989 (period of record 1963-2011).

The U.S. Drought Monitor did not change over the last month for the High Plains region. Severe drought conditions (D2) persisted over south-central Colorado and western Kansas. A large area of moderate drought conditions (D1) across eastern Colorado, western Kansas, and the panhandle of Nebraska also remained. A second area of D1 in southeastern Kansas also existed. In addition, the areas of abnormally dry conditions (D0) in western Wyoming and surrounding the D1 areas remained unchanged.

Upper Colorado River Basin: As reported by the Colorado Climate Center, the March 1st NIDIS (National Integrated Drought Information System) assessment for the Upper Colorado River Basin (UCRB) indicated that February was wetter than average for the Wasatch and Uinta Mountains in Utah, areas of southwestern Wyoming, the Sangre de Cristos in southern Colorado, and the northern mountains of Colorado. Many counties along the Front Range also saw above average precipitation for the month, although because February is not typically a wet month, their water-year-to-date numbers were still at a deficit. The valleys of western Colorado and eastern Utah, the Four Corners region, and the southeastern Plains remained dry for the month. The majority of the SNOTEL stations in the UCRB had high percentile rankings for water-year-to-date (WYTD) precipitation. The Rio Grande and San Juan basins in southern Colorado were the driest with percentile ranks below 50 percent. Some sites in the Rio Grande basin had percentiles below 30 percent. Snowpack around most of the UCRB was above average for this time of year. Normal streamflow was recorded at the end of the month at key gages around the basin. For the month of February, temperatures were below average for most of the UCRB and the eastern Plains of Colorado. Soil moisture was in good condition, with dry soils evident in eastern Colorado. The driest soils were in southeastern Colorado. For the month of February, most of the reservoirs saw their levels drop, with the exception of Lake Dillon, which saw a slight increase in its levels. Lake Powell volume decreased by over half a million acre feet since the beginning of the month, with inflows into the lake slightly below what had been projected. Lake Granby also had a larger decrease in volume, likely to prevent spilling from occurring this summer as its levels were very high at the end of February. Most of the reservoirs ere near or above average levels for this time of year. Lake Powell was at 73 percent of average, but it was expected to have rising levels as snowmelt starts in March and April.

Pacific Islands: According to reports from National Weather Service offices, the Pacific ENSO Applications Climate Center (PEAC), and partners, conditions varied across the Pacific Islands.

February weather systems brought periods of heavy rainfall to the Hawaiian Islands from Kauai to Maui. However, these systems weakened or moved away from the state before reaching the Big Island. As a result, moderate drought, or D1 category conditions in the USDM map, recently returned to the Big Island's eastern slopes and merged with the existing moderate drought area extending from South Point to leeward Kohala. Extreme drought, or D3 conditions, persisted in the Pohakuloa area. Conditions improved enough over leeward Maui to warrant a reduction of severe drought coverage. Severe drought, or D2 category, was limited to the area near Kihei from Kaonoulu to Kamaole. Improvements were also reported on Lanai which resulted in a change from a D2 to D1 depiction over the entire island. The drought status for Molokai remained unchanged over the past month.

Some drought impacts in Hawaii include the following:

  • On Oahu, water levels in the Waimanalo reservoir continued to increase over the past month. However, the State of Hawaii Department of Agriculture maintained a 10 percent cutback in irrigation water use as a precaution.
  • On Molokai, water levels in the Kualapuu reservoir remained relatively steady during the past month. Thus, the State of Hawaii Department of Agriculture has kept in place the mandatory 30 percent cutback in irrigation water consumption.
  • On Maui, pasture conditions have been improving over the past month. The area from Kaonoulu to Kamaole near Kihei has not recovered enough to fully support cattle ranching operations. Water supply levels remained sufficient for upcountry Maui. However, as a precaution, the Maui County Department of Water Supply continued to request a 5 percent reduction in water use by upcountry residents. A 10 percent reduction in water use by central and south Maui residents also remained in effect.
  • On the Big Island, dry conditions over the windward areas have started to produce impacts. Some farmers reported reduced corn, taro, and sweet potato yields due to lack of rainfall. Ranchers have been hauling water to support livestock. Pastures in areas that recovered from previous drought conditions were starting to deteriorate again. Some of the windward area residents on catchment systems have started to hire water hauling services due to below normal rainfall.

On other Pacific Islands, drought conditions continued near the equator as La Niña conditions persisted through February. There were signs that this mature La Niña has begun to weaken, but the westward extent of the drought-producing weather pattern (subsiding air and colder-than-normal sea surface temperatures) remained near 155 E longitude. February rainfall at Kapingamarangi was extremely low with only 0.20 inch, or 1.95 percent of normal. Severe drought conditions extended eastward from about 150 E longitude to beyond the international date line. This area includes Kapingamarangi Atoll, Nauru and the atolls of western Kiribati.

Monthly (February 2011) and 6-month (September 2010-February 2011) precipitation reports included:

  • Pohnpei: 12.25 inches of rain in February (125 percent of normal) with September-February rainfall 92 percent of normal,
  • Nukuoro: 6.66 inches for February (56 percent of normal) with September-February total at 53 percent of normal,
  • Kapingamarangi: 0.20 inch for February (1.95 percent) with September-February at 15 percent of normal,
  • Kosrae: 10.96 inches for February (85 percent) with September-February at 81 percent of normal.

Three-month (December 2010-February 2011) percent of normal rainfall reports included:

  • Chuuk: 93 percent
  • Guam: 143 percent
  • Kapingamarangi: 11 percent
  • Koror: 125 percent
  • Kosrae: 75 percent
  • Kwajalein: 124 percent
  • Majuro: 121 percent
  • Nukuoro: 41 percent
  • Pohnpei: 95 percent
  • Saipan: 111 percent
  • Yap: 113 percent

In the Federated States of Micronesia, adequate rainfall has occurred for most of Pohnpei state and in Kosrae state. Drought conditions remained at Kapingamarangi. The atoll has been extremely dry since August 2010. The overall persistence of this event, along with computer forecast models and past climate history, suggest that this dry pattern should begin to decrease in intensity very slowly during March. Continued implementation of water conservation measures on Kapingamarangi was encouraged. Rainfall at Nukuoro has been variable but probably sufficient for drinking, cooking and most agriculture. Other islands of Pohnpei state have had more than sufficient rainfall. Damage to food crops has likely occurred on Kapingamarangi Atoll as a result of the drought. Some wells and numerous individual solar stills were still producing water for drinking and cooking.

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State/Regional/National Moisture Status
A detailed review of drought and moisture conditions is available for all contiguous U.S. states, the nine standard regions, and the nation (contiguous U.S.):

States
alabama arizona arkansas california colorado connecticut
delaware florida georgia idaho illinois indiana
iowa kansas kentucky louisiana maine maryland
massachusetts michigan minnesota mississippi missouri montana
nebraska nevada new hampshire new jersey new mexico new york
north carolina north dakota ohio oklahoma oregon pennsylvania
rhode island south carolina south dakota tennessee texas utah
vermont virginia washington west virginia wisconsin wyoming

Regional
northeast u. s. east north central u. s. central u. s.
southeast u. s. west north central u. s. south u. s.
southwest u. s. northwest u. s. west u. s.

National
Contiguous United States

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Drought Indicators
The following indicators illustrate the drought conditions this month:

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Contacts & Questions
For additional, or more localized, drought information, please visit:

Global Snow & Ice

NH Snow Cover Extent

Data were provided by the Global Snow Laboratory, Rutgers University. Period of record is 1967-2011 (45 years).

The Northern Hemisphere snow cover extent during February 2011 was above average, marking the 10th largest (26th smallest) on record for the hemisphere. The February snow cover extent for the Northern Hemisphere was 1.74 million square km (0.67 million square miles) above the long-term average of 45.6 million square km (17.6 million square miles). This is the second consecutive February with above-average snow cover. Both the North American and Eurasian land areas had snow cover extent which was above average. According to a satellite analysis by the Rutgers Global Snow Lab, above-average snow cover was observed across the central and northern U.S., eastern China, central Mongolia, and eastern Europe. Below-average snow cover was observed across western Europe and western China. For the winter period (December-February), the Northern Hemisphere experienced its third largest snow cover extent on record at 1.98 million square km (0.76 million square miles) above the average of 45.2 million square km (17.5 million square miles). The winter seasons of 1977-1978 and 2009-2010 had larger snow cover extents.

During February 2011, the North American snow cover extent was above average, ranking as the 8th largest (38th smallest) on record. This is the fifth consecutive February with above-average snow cover for North America. The monthly average snow cover extent was 0.75 million square km (290,000 square miles) above the long-term average of 17.1 million square km (6.6 million square miles). According to data from the Rutgers Global Snow Lab, Canada, the contiguous U.S., and Alaska all had above-average snow coverage for the month. An active storm pattern across the western, central, and northern portions of the U.S. contributed to the above average snow cover extent for February. During the winter period (December-February), North America experienced its third largest snow cover extent on record at 0.88 million square km (340,000 square miles) above the average of 17.2 million square km (6.6 million square miles). The winter seasons of 1978-1979 and 2009-2010 both had larger snow cover extents.

Eurasian snow cover extent during February 2011 was also above average, ranking as its 13th largest (33rd smallest) on record. This is the second consecutive February with above-average snow cover extent for Eurasia. The February 2011 Eurasian snow cover extent was 0.99 million square km (382,000 square miles) above the long-term average of 28.6 million square km (11.0 million square miles). The winter (December-February) period snow cover extent for Eurasia was above average. The seasonal snow cover extent anomaly of 1.1 million square km (425,000 square miles) ranks as the fourth largest (42nd smallest) on record, behind the winters of 1977-1978, 2002-2003, and 1971-1972.

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Sea Ice Extent

According to the National Snow and Ice Data Center (NSIDC), the Northern Hemisphere sea ice extent — which is measured from passive microwave instruments onboard NOAA satellites — averaged for February 2011, was 14.36 million square km (5.54 million square miles), 8.2 percent below the 1979-2000 average. This tied with February 2005 as the smallest February Arctic sea ice extent since records began in 1979, and the third consecutive month (along with December 2010 and January 2011) with a record low monthly ice extent. February 2011 is the 13th consecutive February with below average-sea ice extent for the Northern Hemisphere. The Arctic sea ice during January was below average on both the Atlantic and Pacific sides of the Arctic. Most notably, sea ice extent was low in the Sea of Okhotsk in the Pacific Ocean and the Gulf of St. Lawrence and Labrador Sea on the Atlantic side. These regions experienced temperatures ranging from 2–7°C (4–13°F) above average for the month. Northern Hemisphere sea ice extent for February has decreased at a rate of 3.0 percent per decade. The Arctic sea ice will continue to expand and will reach its annual maximum during March.

The February 2011 Southern Hemisphere sea ice extent was below average for the month — 16.1 percent below the 1979-2000 average. This marks the third smallest February Southern Hemisphere sea ice extent on record, behind February 1993 and 1997. The February 2011 ice extent is also in stark contrast to the ice extent in February 2010 which was 7.35 percent above average. February Antarctic sea ice extent has increased at an average rate of 1.8 percent per decade, although there is considerable inter-annual variability. The annual minimum Southern Hemisphere sea ice extent likely occurred at the end of February, when the Antarctic sea ice extent dipped to 1.76 million square km (680,000 square miles).

For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.

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Upper Air

Contents of this Section:


Note: Beginning in December 2010, all data are reported here with respect to the 1981–2010 base period. Prior to December 2010, radiosonde data were reported with respect to the 1961–1990 base period and satellite data were reported with respect to the 1979–1998 base period. Remote Sensing Systems continues to provide data to NCDC with respect to the 1979–1998 base period; however, NCDC readjusts the data to the 1981–2010 base period so that the satellite measurements are comparable. This change provides a more consistent comparison between the various datasets.


Note: Effective with the January 2011 report, Remote Sensing Systems (RSS) transitioned to a new version (3.3) of the RSS MSU/AMSU atmospheric temperature datasets. Information about the differences between version 3.2 and 3.3 is available.


Upper Air Highlights


  • University of Alabama Huntsville satellite analyses report that the lower troposphere Febuary 2011 temperature was 0.01°C (0.02°F) below the 1981–2010 average, the 17th coolest (17th warmest) since satellite records began in 1979. The seasonal December–February period was the 13th warmest on record.

  • Remote Sensing Systems satellite analyses report a lower troposphere February temperature anomaly of 0.06°C (0.10°F) below the 1981–2010 base period, the 14th coolest (20th warmest) on record. The seasonal December–February period ranked as 20th coolest (14th warmest).

  • University of Alabama Huntsville satellite analyses report a February 2011 mid troposphere temperature anomaly of 0.14°C (0.25°F) below average, the 10th coolest (24th warmest) such period on record. When these analyses are adjusted to remove stratospheric influence, the anomaly decreases to 0.09°C (0.18°F) below average, the 13th coolest (21st warmest) on record.

  • Remote Sensing Systems satellite analyses report a February 2011 mid troposphere temperature anomaly of 0.08°C (0.15°F) below average, the 13th coolest (21st warmest) such period on record. When these analyses are adjusted to remove stratospheric influence, the anomaly decreases to 0.03°C (0.05°F) below average, the 18th coolest (16th warmest) on record.

  • For the lower stratosphere, University of Alabama Huntsville satellite data indicate that Febuary 2011 was the 15th coolest February in the 33-year period of record, while Remote Sensing System satellite analyses report that February 2011 was the 17th coolest (17th warmest) February. Both report that the December–February period was 18th coolest (16th warmest) on record.

  • Troposphere

    Temperatures above the Earth's surface are measured within the lower troposphere, middle troposphere, and stratosphere using in-situ balloon-borne instruments (radiosondes) and polar-orbiting satellites (NOAA's TIROS-N). The radiosonde and satellite records have been adjusted to remove time-dependent biases (artificialities caused by changes in radiosonde instruments and measurement practices as well as changes in satellite instruments and orbital features through time). Global averages from radiosonde data are available from 1958 to present, while satellite measurements date back to 1979.

    Lower Troposphere

    Current Month | Seasonal | Year-to-date

    These temperatures are for the lowest 8 km (5 miles) of the atmosphere. Information on the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS) sources of troposphere data is available.

    February Anomaly Rank
    (out of 33 years)
    Warmest (or Next Warmest)
    Year on Record
    Trend
    *UAH low-trop -0.01°C/-0.02°F 17th warmest 1998 (+0.66°C/+1.19°F) +0.13°C/decade
    RSS low-trop -0.06°C/+0.010°F 20th warmest 1998 (+0.63°C/+1.13°F) +0.14°C/decade

    *Version 5.3

    December–February Anomaly Rank
    (out of 33 years)
    Warmest (or Next Warmest)
    Year on Record
    Trend
    *UAH low-trop +0.06°C/+0.10°F 13th warmest 1998 (+0.46°C/+0.82°F) +0.13°C/decade
    RSS low-trop +0.02°C/+0.03°F 14th warmest 1998 (+0.43°C/+0.77°F) +0.13°C/decade

    *Version 5.3

    January–
    February
    Anomaly Rank
    (out of 33 years)
    Warmest Year on RecordTrend
    *UAH low-trop +0.00°C/+0.00°F 17th warmest 1998 (+0.57°C/+1.03°F) +0.13°C/decade
    RSS low-trop -0.05°C/-0.09°F 18th warmest 1998 (+0.53°C/+0.95°F) +0.14°C/decade

    *Version 5.3


    Mid-troposphere

    Current Month / Seasonal Year-to-date

    These temperatures are for the atmospheric layer centered in the mid-troposphere (approximately 3–10 km [2–6 miles] above the Earth's surface), which also includes a portion of the lower stratosphere. (The Microwave Sounding Unit [MSU] channel used to measure mid-tropospheric temperatures receives about 25 percent of its signal above 10 km [6 miles].) Because the stratosphere has cooled due to increasing greenhouse gases in the troposphere and losses of ozone in the stratosphere, the stratospheric contribution to the tropospheric average, as measured from satellites, may create an artificial component of cooling to the mid-troposphere temperatures. The University of Washington (UW) versions of the UAH and RSS analyses attempt to remove the stratospheric influence from the mid-troposphere measurements, and as a result the UW versions tend to have a larger warming trend than either the UAH or RSS versions. For additional information, please see NCDC's Microwave Sounding Unit page.

    The radiosonde data used in this global analysis were developed using the Lanzante, Klein, Seidel (2003) ("LKS") bias-adjusted dataset and the First Difference Method (Free et al. 2004) (RATPAC). Additional details are available. Satellite data have been adjusted by the Global Hydrology and Climate Center at the University of Alabama in Huntsville (UAH). An independent analysis is also performed by Remote Sensing Systems (RSS) and a third analysis has been performed by Dr. Qiang Fu of the University of Washington (UW) (Fu et al. 2004)** to remove the influence of the stratosphere on the mid-troposphere value. Global averages from radiosonde data are available from 1958 to present, while satellite measurements began in 1979.

    Radiosonde measurements indicate that, for the January–February year-to-date period, temperatures in the mid-troposphere were 0.17°C (0.31°F) above average, resulting in the 9th warmest January–February period (out of 54 years) since global radiosonde measurements began in 1958. Various satellite analyses of the January–February year-to-date period for the middle troposphere ranked between 19th and 25th warmest in the 33-year satellite record.

    Radiosonde measurements indicate that mid-tropospheric temperatures were 0.23°C (0.41°F) above average during the Northern Hemisphere winter season, giving December–February a rank of 8th warmest on record. The table below shows that the various satellite measurements for the season.

    The global mid-troposphere temperatures were well above average during February 2010. As shown in the table below, satellite measurements for February 2010 ranked second warmest on record, behind 1998.

    February Anomaly Rank
    (out of 33 years)
    Warmest Year on Record Trend
    *UAH mid-trop -0.14°C/-0.25°F 24th warmest 1998 (+0.65°C/+1.17°F) +0.03°C/decade
    RSS mid-trop -0.08°C/-0.15°F 18th warmest 1998 (+0.61°C/+1.10°F) +0.10°C/decade
    UW-*UAH mid-trop -0.09°C/-0.16°F 21st warmest 1998 (+0.75°C/+1.34°F) +0.09°C/decade
    UW-RSS mid-trop -0.03°C/-0.05°F 16th warmest 1998 (+0.69°C/+1.24°F) +0.15°C/decade

    *Version 5.3

    December–February Anomaly Rank
    (out of 33 years)
    Warmest (or Next Warmest)
    Year on Record
    Trend
    *UAH mid-trop -0.09°C/-0.16°F 24th warmest 1998 (+0.44°C/+0.79°F) +0.02°C/decade
    RSS mid-trop -/0.05°C/-0.09°F 20th warmest 1998 (+0.42°C/+0.75°F) +0.07°C/decade
    UW-*UAH mid-trop -0.04°C/-0.06°F 19th warmest 1998 (+0.52°C/+0.94°F) +0.08°C/decade
    UW-RSS mid-trop +0.00°C/+0.00°F 16th warmest 1998 (+0.48°C/+0.87°F) +0.13°C/decade
    RATPAC +0.23°C/+0.41°F 8thwarmest 2010 (+0.55°C/+0.99°F) +0.16°C/decade

    *Version 5.3

    January–
    February
    Anomaly Rank
    (out of 33 years)
    Warmest (or Next Warmest)
    Year on Record
    Trend
    *UAH mid-trop -0.14°C/-0.25°F 25th warmest 1998 (+0.56°C/+1.01°F) +0.03°C/decade
    RSS mid-trop -0.09°C/-0.16°F 20th warmest 1998 (+0.53°C/+0.95°F) +0.09°C/decade
    UW-*UAH mid-trop -0.10°C/-0.18°F 20th warmest 1998 (+0.66°C/+1.19°F) +0.08°C/decade
    UW-RSS mid-trop -0.04°C/-0.07°F 19th warmest 1998 (+0.62°C/+1.12°F) +0.15°C/decade
    RATPAC +0.17°C/+0.31°F 9th warmest 2010 (+0.77°C/+1.39°F) +0.15°C/decade

    *Version 5.3

    Note: RATPAC's rank is based on records that began in 1958 (54 years).

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    Stratosphere

    Current Month | Seasonal

    The table below summarizes stratospheric conditions for February 2010. On average, the stratosphere is located approximately 16–23 km (10–14 miles) above the Earth's surface. Over the last decade, stratospheric temperatures have been below average in part due to the depletion of ozone. The large positive anomaly in 1982 was caused by the volcanic eruption of El Chichon in Mexico, and the sharp jump in temperature in 1991 was a result of the eruption of Mt. Pinatubo in the Philippines. In both cases the temperatures returned to pre-eruption levels within two years.

    February Anomaly Rank
    (out of 33 years)
    Coolest Year on Record
    *UAH stratosphere -0.15°C (-0.27°F) 15th coolest 2006 (-0.57°C/-1.03°F)
    RSS stratosphere -0.10°C (-0.19°F) 17th coolest 2006 (-0.58°C/-1.04°F)

    *Version 5.3

    December–February Anomaly Rank
    (out of 33 years)
    Coolest Year on Record
    *UAH stratosphere -0.14°C (-0.25°F) 16th coolest 2006 (-0.53°C/-0.95°F)
    *RSS stratosphere -0.09°C (-0.17°F) 16th coolest 2006 (-0.51°C/-0.92°F)

    *Version 5.3

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    References

    Christy, John R., R.W. Spencer, and W.D. Braswell, 2000: MSU tropospheric Temperatures: Dataset Construction and Radiosonde Comparisons. J. of Atmos. and Oceanic Technology, 17, 1153-1170.

    Free, M., D.J. Seidel, J.K. Angell, J. Lanzante, I. Durre and T.C. Peterson (2005) Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC): A new dataset of large-area anomaly time series, J. Geophys. Res., 10.1029/2005JD006169.

    Free, M., J.K. Angell, I. Durre, J. Lanzante, T.C. Peterson and D.J. Seidel(2004), Using first differences to reduce inhomogeneity in radiosonde temperature datasets, J. Climate, 21, 4171-4179.

    Fu, Q., C.M. Johanson, S.G. Warren, and D.J. Seidel, 2004: Contribution of stratospheric cooling to satellite-inferred tropospheric temperature trends. Nature, 429, 55-58.

    Lanzante, J.R., S.A. Klein, and D.J. Seidel (2003a), Temporal homogenization of monthly radiosonde temperature data. Part I: Methodology, J. Climate, 16, 224-240.

    Lanzante, J.R., S.A. Klein, and D.J. Seidel (2003b), Temporal homogenization of monthly radiosonde temperature data. Part II: trends, sensitivities, and MSU comparison, J. Climate, 16, 241 262.

    Mears, Carl A., M.C. Schabel, F.J. Wentz, 2003: A Reanalysis of the MSU Channel 2 tropospheric Temperature Record. J. Clim, 16, 3650-3664.

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    Wildfires


    Updated: 7 March 2011

    February is not typically considered part of the U.S. wildfire season, with fire activity typically being low during the month. However, dry and warm conditions across the southern and southeastern U.S., particularly the second half of the month, were associated with an early start to the 2011 wildfire season. Please see the monthly temperature and precipitation discussion for more information. The number of new wildfires and the acreage burned during the month were much-above average. The 8,226 new wildfires that occurred during February 2011, marked the highest February wildfire count on record, and the 187,021 acres (75,685 hectares) was the second most February acreage burned, behind February 2008 when 214,183 acres (86,677 hectares) burned. Wildfire records for the U.S. date back to 2000. On February 4th, there were 20 large wildfires burning across the U.S. — ten in Oklahoma, four each in Arkansas and Texas, and one each in Arizona and Florida. By the middle of the month, large wildfire activity shifted more eastward, with 16 large wildfires burning nationally — six in Missouri, two each in Alabama, Florida, North Carolina, Virginia, and one in both Texas and Georgia. By the end of the month, wildfire activity was concentrated in the Southern Plains and the Florida Peninsula. On the 28th, there were 25 large fires burning in the U.S., 18 in Texas, five in Florida, and one each in New Mexico, and Virginia.

    2011 Wildfire Statistics

    (Source: NIFC)
    Year–To–Date Totals as of February 28th Nationwide Number of Fires Nationwide Number of Acres Burned
    02/28/2011 9,752 204,373
    02/28/2010 2,302 34,543
    02/28/2009 7,976 177,597
    02/28/2008 5,829 254,987
    02/28/2007 4,178 35,351
    02/28/2006 5,936 411,011
    02/28/2005 4,192 28,149
    02/28/2004 4,587 55,173
    02/28/2003 3,994 49,695
    02/28/2002 6,032 65,566
    02/28/2001 7,792 163,206
    02/28/2000 8,467 208,967
    5–yr average
    (2006 – 2010)
    5,244 182,698
    10–yr average
    (2001 – 2010)
    5,571 134,931

    According to statistics from the National Interagency Fire Center (NIFC), at the end of February, the nationwide number of fires year-to-date was 9,752, which burned 204,373 acres (82,707 hectares), with an average of 21.0 acres (8.5 hectares) per fire. This marks the largest number of fires for the year-to-date period and the fourth largest acreage burned since records began in 2000. During February, an estimated 187,021 acres (75,684 hectares) burned across the U.S., which is more than twice the 2000-2010 average. A total of 8,226 fires were reported during the month, which is also more than two times the average. The average number of acres burned per fire was 22.7 acres (9.2 hectares), which was also above average.

    According to the U.S. Drought Monitor the overall size of the drought footprint changed little during February, but many locations that were experiencing drought at the beginning of the month experienced worsening drought conditions during February. By March 1st, most of the West continued to be drought free, with the exception of parts of the Southwest. Across southern New Mexico, Arizona, and western Texas, drought conditions worsened from moderate to severe drought during the month. Severe drought also expanded across the Front Range in Colorado and across central Oklahoma. Severe and extreme drought conditions expanded across most of Texas, and the footprint of extreme drought grew across the Lower Mississippi River Valley. Moderate drought conditions developed across northern Alabama and Mississippi and severe drought covered much of the Carolina piedmont. The overall size of the extreme drought in Florida shrank, but moderate-to-severe drought continued to plague most of the state on March 1st. Across Hawaii, precipitation amounts were mixed, the overall size of the extreme drought footprint shrank, but moderate drought developed over much of the Big Island. In Alaska, abnormally dry conditions expanded into central parts of the state.

    As stated above, wildfire activity across the Southern Plains of the U.S. was extremely high during February, particularly across parts of Texas. Seventy one individual wildfires broke out across Texas on the weekend of February 25th, burning nearly 137,700 acres (55,725 hectares) according to the Texas Forest Service. The acreage burned in Texas accounted for nearly three-quarters of all acres burned nationwide during February. The wildfires were driven by warm, dry, and windy conditions. On the 27th, the temperature in Laredo, Texas reached 103°F (39.4°C), which was the first 100°F reading for the year for any location in the U.S., and it broke a daily record for the city. Several fires reached over 20,000 acres (8,094 hectares) in size, particularly in Potter, Motley, and Andrews counties. Interstate Highway 20 was shut down for several hours on the 27th after heavy smoke from the fires limited visibility. An automobile accident caused by the smoke left one dead. Across the state, 60 homes were destroyed over the weekend. The weather conditions improved on the 28th when moisture and calm winds returned to the region.

    A large wildfire in western Virginia took 10 days to fully contain, and burned nearly 3,500 acres (1,416 hectares), 10 miles west of Harrisonburg in the George Washington National Forest. The fire burned between the 18th and 28th. Several roads were forced to close due to the fire and the associated smoke, including U.S. Highway 33. Several miles east of Harrisonburg, in the Shenandoah National Park, another fire burned 1,800 acres (728 hectares) during the same period — the most acres burned in the national park in over 100 years. Both fires were contained by March 1st, after beneficial rains came to the region, aiding firefighters. No personal property was lost in the fires, although over 300 homes were threatened.

    According to the U.S. Forest Service (USFS) – Wildland Fire Assessment System, on February 1st, high fire danger was confined to the Great Basin and the Southwest. By the 15th, high fire danger expanded into the Southern Plains and the along Eastern Seaboard. High fire danger was reported across the Great Basin, the Southwest, the central Plains, and the East Coast from Georgia into New Jersey. Precipitation the last week of the month quieted the fire danger across parts of the West, but high fire danger continued in New Mexico, southern Texas, and along the Southeast coast, where dry conditions persisted.

    According to the U.S. Forest Service (USFS) – Wildland Fire Assessment System, at the beginning of February, low fuel moistures of all sizes were present in the West, with the exception of the Pacific Northwest and the Sierra Nevada Mountains. Dry larger fuels (100-hour and 1,000-hour fuel moistures) extended eastward into New Mexico, Oklahoma, and Texas. Dry conditions the first half of the month for most of the country caused a large expansion of low 10-hour fuel moistures by the 15th. Low 10-hour fuel moistures were present in all locations of the U.S., except the Pacific Northwest, the central Rockies, and the western Great Lakes. The lowest 10-hour fuel moistures were present across the Great Basin, the Southwest, and the Mid-Atlantic. Low 100-hour fuel moistures were also widespread across the southern two-thirds of the country, except for the central Rockies and the Gulf Coast. Dry large fuels (1,000-hour fuel moistures) were confined to the Southwest. By the end of the month, an active storm pattern in the West, Northern Plains, Great Lakes, and Northeast moistened 10-hour and 100-hour fuel moistures there. Low 10-hour and 100-hour fuel moistures were reported in the Florida Peninsula, western Texas, and southern New Mexico. The only low 1,000-hour fuel moistures across the U.S. continued in the Southwest.

    According to the U.S. Forest Service (USFS) – Wildland Fire Assessment System, at the beginning of the month, high Keetch–Byram Drought Index (KBDI) values were reported across southern Florida, most of Texas, central Nevada, and southern Arizona. The KBDI remained generally unchanged by the 15th. On the 28th, the high KBDI values across southern Florida expanded into northern portions of the peninsula, and in Texas the high KBDI values expanded and increased in the western regions of the state.


    Citing This Report

    NOAA National Climatic Data Center, State of the Climate for February 2011, published online March 2011, retrieved on April 17, 2014 from http://www.ncdc.noaa.gov/sotc/2011/2.