Entire Report - November 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.

Maps and Graphics

Temperature and Precipitation Ranks
U.S. Percentage Areas
More Information

National Overview:



November Extreme Weather/Climate Events
  • Climate Highlights — November
  • Both November and the autumn season of September to November were warmer than average, using temperatures averaged across the contiguous United States. Precipitation totals across the country were also above average during November, but near the long-term average for the autumn season. This monthly analysis is based on records dating back to 1895
  • The average U.S. temperature in November was 44.3 degrees F, or 1.8 degrees F above the 1901-2000 long term average, while the average autumn temperature was 55.5 degrees F, or 1.3 degrees F above average. Precipitation averaged across the nation during November, was 2.33 inches, or 0.21 inch above average.
  • During November, the eastern half of the country experienced above-average temperatures. The warmest temperature anomalies, which is the temperature compared to the 20th century average, occurred across the Midwest, Mid-Atlantic, and Northeast, with thirteen states across these areas having November temperatures among their ten warmest on record.
  • Cooler-than-average temperatures were present across parts of the West and Northwest, with six states having November temperatures below average.
  • Precipitation during November was variable from region to region. Several storm systems brought above-average precipitation to the Ohio Valley and parts of the South. Eight states had November precipitation totals ranking among their ten wettest.
  • Below-average precipitation was observed across parts of the West, and parts of the northern United States and south. Minnesota tied its 9th driest November on record, with only 0.35 inch of precipitation — 0.95 inch below average.
  • As of November 29th, about six percent of the contiguous United States remained in the worst category of drought, called D4 or exceptional drought, a decrease from the nearly 9 percent at the beginning of the month. Drought conditions lessened across Arkansas, Kansas, and Oklahoma, where there was above-normal precipitation during November.
  • The 2011 North Atlantic hurricane season officially came to a close on November 30th, after an above-average season for the basin. There were 19 named storms during the 2011 season, tying with three other years (2010, 1995, and 1887) as the 3rd busiest season on record. Seven of the named storms became hurricanes, which is near average. Only Tropical Storm Lee and Hurricane Irene made landfall in the United States during 2011.
  • A large and powerful extratropical cyclone slammed into western Alaska in early November, with extremely high tides, strong winds, heavy rain, and blizzard conditions. Winds gusted to over 80 mph and the storm surge topped 8 feet, marking the strongest storm to impact the region in decades.
  • A powerful Santa Ana windstorm whipped through mountain passes and canyons across the West and Southwest beginning on November 30th and continuing into December. The near-hurricane force winds were driven by the interaction between a strong high pressure system in the northwest and a low pressure system moving through the southwest. The high pressure system led to Portland, Oregon recording its second highest atmospheric pressure reading (30.76”) on record.
  • The November 2011 Residential Energy Demand Temperature Index (REDTI) was 25.7, which is the 14th lowest November value in 117 years.
  • A list of select November temperature and precipitation records can be found here.
  • Climate Highlights — Autumn (September-November)
  • During the autumn period, the United States, as a whole, experienced above-average temperatures with a nationallyaveraged temperature of 55.5 degrees F. This was 1.3 degrees F above average.
  • Most states had autumn temperatures which were near to above average. Massachusetts, Rhode Island, and Vermont had their record warmest fall. Eight other states had an average temperature that was one of the ten warmest on record. Conversely, four states in the Southeast and along the Gulf Coast had below-average autumn temperatures.
  • The nationally-averaged precipitation total during autumn was near average. Wet conditions were present from the Ohio Valley and into the Northeast. Parts of the upper Midwest were drier than average, and Minnesota had its third driest autumn on record.
  • The United States Climate Extremes Index (USCEI) and Regional Climate Extremes Index (RCEI) are sensitive to extremes in temperature, rainfall, dry streaks, drought, and tropical cyclones on the national and regional scale, respectively. For the autumn period, the Northeast region had its second highest RCEI value due to warm minimum temperatures, wet Palmer Drought Severity Index (PDSI), and days with precipitation.
  • Climate Highlights — Year-to-Date (January-November)
  • For the first 11 months of 2011, the U.S. was warmer than average. Much of the warmth was anchored across the Southern Plains and along the Eastern Seaboard. Delaware and Texas were record warm for the January-November period with statewide temperatures 3.2 degrees F and 2.5 degrees F above their long-term averages, respectively. Only Oregon, South Dakota, and Washington were cooler than average during the period.
  • Nationally-averaged precipitation totals for January-November were near the long-term average, but significant differences between regions existed. Texas was record dry for the 11-month period, with a statewide precipitation total of 12.0 inches which stands at 14.0 inches less than average. For the year-to-date period, the Ohio Valley and Northeast had very wet conditions with Connecticut, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, and Vermont each having the wettest January-November period on record.
  • For the year-to-date period, the USCEI ranked at the 12th highest value on record. A large aerial extent of warm maximum and minimum temperatures, wet and dry PDSI, and days with precipitation contributed to the elevated USCEI value. On a regional level, the Northeast region and the South region both had their second highest RCEI values during January-November 2011. Across the Northeast, warm minimum temperatures, wet PDSI, 1-day precipitation totals, and days with precipitation were the most significant contributing factors. In the South region, warm maximum temperatures and dry PDSI were the most significant contributing factors to the high index value.
  • The autumn 2011 REDTI is 19.5, which is the 11th lowest value in 117 years.
  • The number of billion-dollar weather/climate disasters in the United States during 2011 rose to 12 for the year-to-date. This record year breaks the previous record of nine billion-dollar weather/climate disasters during a single year, which occurred in 2008. The aggregate damage from these 12 events is approximately 52 billion U.S. Dollars. The two new Billion Dollar weather and climate events added to the 2011 total include:
    • Separation of Texas, New Mexico, Arizona wildfires from Southern Plains Drought and Heatwave as the wildfires are separately over one billion U.S. dollars.
    • Addition of the June 18-22, 2011, Midwest/Southeast Tornadoes and Severe Weather which just recently exceeded the one billion U.S. dollars threshold

Alaska Temperature and Precipitation:

  • Alaska had its 6th coolest November on record, with a temperature 8.2 °F (4.55°C) below the 1971–2000 average.
  • Alaska had its 18th coolest September-November on record, with a temperature 1.7 °F (0.95°C) below the 1971–2000 average.
  • Alaska had its 43rd coolest year-to-date period on record, with a temperature 0.6 °F (0.31°C) below the 1971–2000 average.
  • Alaska had its 41st driest November since records began in 1918, with an anomaly that was 5.0 percent below the 1971–2000 average.
  • Alaska had its 47th wettest September-November on record, with an anomaly that was 1.1 percent below the 1971–2000 average.
  • Alaska had its 41st driest year-to-date period on record, with an anomaly that was 2.3 percent above 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)
  • November’s temperatures averaged 44.0 degrees F (6.7 degrees C), making this the third warmest November in the Northeast since 1895. This month’s average was 4.3 degrees F (2.4 degrees C) above normal and 4.5 degrees F (2.5 degrees C) warmer than November 2010. It was the eighth consecutive month with above normal temperatures. Each of the states in the region had averages that were within the top 14 warmest in 117 years. Delaware and Maine ranked 2nd warmest, while New Hampshire, Rhode Island and Vermont saw their 3rd warmest November since 1895. Departures ranged from +2.9 degrees F (1.6 degrees C) in Maryland to +5.6 degrees F (3.1 degrees C) in Vermont. It was the 4th warmest autumn (September November) in the Northeast since 1895. The three-month average was 52.8 degrees F (11.6 degrees C), which was 2.8 degrees F (degrees C) warmer than normal. Each of the region’s states averaged warmer than normal; three states, Massachusetts, Rhode Island, and Vermont, saw their warmest autumn in 117 years. With eleven months of above normal temperatures, it’s no surprise that the January through November average was also warmer than normal. The year-to-date average of 50.3 degrees F (10.2 degrees C) was 1.2 degrees F (0.7 degrees C) warmer than normal. It was the 13th warmest January through November in the Northeast since 1895 and the warmest January through November in Delaware.
  • After three wetter than normal months, precipitation totals averaged on the dry side in November. The Northeast total of 3.20 inches (81.3 mm) was 84 percent of normal. New Jersey (106 percent), Pennsylvania (103 percent) and West Virginia (122 percent) were the only states with above normal totals. Departures in the drier-than-normal states ranged from 48 percent of normal in Maine to 99 percent of normal in Delaware. It was the 11th driest November in Maine since recordkeeping began in 1895. Autumn (September November) precipitation totals averaged 14.69 inches (373 mm), which was 127 percent of normal. The Northeast saw its fifth wettest autumn in 117 years; with 18.25 inches (464 mm), Pennsylvania saw its wettest autumn on record. West Virginia’s three month total of 15.08 inches (383 mm) made this the 2nd wettest autumn since 1895 and Maryland’s total of 16.96 inches (431 mm) ranked 3rd wettest on record. Six states Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, and Vermont - and the region overall saw their wettest January through November in 117 years. New York’s eleven-month total of 50.48 inches (128 cm) surpassed the all-time annual record of 50.18 inches (127 cm) The January through November totals in Connecticut, New Jersey and Pennsylvania are within one inch (25.4 mm) of their annual record amounts.
  • For more information, please go to the Northeast Regional Climate Center Home Page.
  • Midwest Region: (Information provided by the Midwest Regional Climate Center)
  • November temperatures were above normal across the Midwest. Temperature ranged from 1 degree F (1 degree C) to 6 degrees F (3 degrees C) above normal for the month. The second and fourth weeks of the month were warm across the region while pockets of below normal occurred in the first and third weeks. Daily records were heavily dominated by record highs with more than 400 new or tied records compared to about a dozen record lows. Fall (September-November) temperatures averaged near normal in the southern Midwest and 2-4 degrees F (1-2 degrees C) above normal in the northern half of the region.
  • November precipitation ranged widely in November. Parts of Minnesota and northwest Iowa received less than 0.10” (3 mm) and amounts increased to the south and east with the boot heel of Missouri and western Kentucky topping 10” (254 mm) for the month. Totals were near twice normal or more in swaths across northern Missouri to western Illinois and from the boot heel of Missouri up the Ohio River Valley and northward to western Lake Erie. Fall precipitation also ranged widely across the region. Three-month totals ranged from under 2” (51 mm) to nearly 20” (508 mm).
  • Drought conditions in the Midwest shifted to the west and north during November, continuing the migration seen in the fall season as a whole. November rains in Missouri, Illinois, and southeast Iowa led to improvements, or elimination, of drought conditions while dry conditions to the northwest led to degradations in Minnesota and northwest Iowa where Severe Drought designated areas expanded during the month.
  • Wet conditions in the eastern half of the Midwest saw no relief as heavy rains fell in November. Harvest in Ohio was behind schedule due to wet soils and continued rains. Minor to moderate flooding was reported in Indiana, Ohio, and Kentucky late in the month. Cincinnati’s airport station has already set an annual (calendar year) record precipitation total of 66.76” (1695 mm) with a month left in the year. The total is 27.72” (704 mm) above normal and already 9.18” (233 mm) above the old record from 1990. Records for the station extend back to 1869. Several nearby Kentucky stations are near their annual records as well.
  • All but a handful of the November severe weather reports in the Midwest came on the 14th with the passing of a cold front that triggered severe thunderstorms in the eastern half of the region. The only two November tornadoes in the Midwest occurred that day. One was reported near Mahomet, Illinois (Champaign County) in the early afternoon. Damage included several trees and one house. The second tornado was an EF1 rated storm that touched down near Paoli, Indiana (Orange County) after dark. The tornado track was two miles (3.2 km) long, damaging homes and businesses as well as the county courthouse and Paoli Police Department. There were several dozen additional severe hail and wind reports on the 14th extending from eastern Illinois and southeast Missouri, across Indiana and northern Kentucky, through Ohio.
  • 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 in November were near normal across most of the Southeast region, except across Virginia and central portions of North Carolina where monthly temperatures were between 2 and 4 degrees F (1.1 to 2.2 degrees C) above average. A cold spell occurred over a large portion of the region from the 11th to 13th of the month following the passage of a cold front. Several locations across Alabama, Georgia, and northern Florida (e.g. Jacksonville, FL, Gainesville, FL, and Mobile, AL) recorded their first freeze of the season, nearly one month earlier than normal. The warmest temperatures of the month occurred several days after the cold spell as a ridge of high pressure off the East Coast advected warm air into the region. Over 150 daily maximum and over 200 daily high minimum temperature records were tied or broken between the 14th and 17th of the month.
  • As in October, precipitation was highly variable across the Southeast. Monthly totals were between 150 and 200 percent of normal across northern portions of Alabama, Georgia, and South Carolina, and across western portions of North Carolina and Virginia. Brevard, NC recorded its second wettest November on record with 10.85 inches (275.6 mm) of precipitation, including 6.24 inches (158.5 mm) on the 29th of the month. Greensboro, NC recorded 6.78 inches (172.2 mm) of precipitation, making it the third wettest November in a record extending back to 1903. In contrast, the driest locations across the Southeast were found across the southern two-thirds of Florida, where monthly precipitation totals were between 5 and 25 percent of normal. Daytona Beach, FL recorded just 0.06 inches (1.5 mm) of precipitation, making it the second driest November in a record extending back to 1922. Elsewhere across the region, monthly precipitation was between 50 and 75 percent of normal, including the eastern slopes and interior mountains of Puerto Rico. Precipitation across the rest of the island was between 150 and 300 percent of normal. The cold spell that occurred in the middle of the month resulted in trace amounts of snowfall across the higher elevations of western North Carolina and Virginia. Several locations across the interior of the region reported measurable snowfall from the 28th to the 30th of the month as an area of low pressure tracked through the Tennessee and Ohio River Valleys. Up to 3 inches (76.2 mm) were reported in northern Alabama and western North Carolina, while Caesar’s Head in northwestern South Carolina recorded just its fourth measurable November snowfall ever with 1 inch (25.4 mm) on the 30th of the month.
  • There were 110 reports of severe weather across the Southeast in November, including an outbreak of 11 tornadoes that occurred on the 16th and 17th of the month. Four of these tornadoes occurred in Alabama, including an EF-2 tornado that injured one person in Sumter County. Another two tornadoes were confirmed in Georgia, including an EF-2 tornado that injured two people and severely damaged three school buildings in Harris County. Damaging thunderstorm winds were responsible for the death of a woman in Forsyth County, GA when a tree fell on her car. Two tornadoes were confirmed in South Carolina, including an EF-2 tornado near Rock Hill in York County that tossed and rolled a mobile home nearly 75 yards (68.6 meters), killing two occupants inside. Three tornadoes were confirmed in North Carolina, including an EF-2 tornado that tracked across Davidson and Randolph Counties. Two individuals were killed when the home they were occupying slid off its foundation and rolled down a steep embankment.
  • For the second consecutive month, there were very few changes to the Drought Monitor across the Southeast region. By the end of November, more than half of the region was classified as being in drought, with nearly two-thirds of Georgia still classified as being in extreme drought. At one point during the month, the water level at Lake Lanier in northern Georgia was dropping at a rate of one foot (304.8 mm) per week. According to the North Carolina State Climate Office, adequate topsoil moisture conditions aided in the successful planting of winter grains. In contrast, the Florida State Climate Office reported that the cold spell near the middle of the month damaged vegetable crops across the Florida Panhandle, while warm temperatures and dry weather increased disease pressures to crops in parts of south Florida.
  • 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)
  • Overall, the High Plains Region experienced a warm and dry November. These conditions were favorable for crop producers and allowed most of the remaining harvesting activities across the Region to be completed. The largest temperature departures were in the Dakotas, northern Nebraska, and pockets of eastern Colorado. In these areas, temperatures were generally 4-6 degrees F (2.2-3.3 degrees C) above normal. Although a few locations had temperature departures which were 6-8 degrees F (3.3-4.4 degrees C) above normal, monthly temperature records were not set this month. Below normal temperatures were confined to western Wyoming and a few isolated locations throughout the Region. While monthly temperature records were not set this month, many locations set new daily temperature records on or near Thanksgiving. Interestingly, for many locations across the Dakotas the warmest and coldest temperatures of the month occurred near Thanksgiving. For instance, Bismarck, North Dakota had its lowest temperature of the month, 0 degrees F (-17.8 degrees C), on November 20th and just three days later set a new record high of 62 degrees F (16.7 degrees C) on November 23rd. Thanksgiving was unusually warm across the Region this year and many locations set new record highs for the day. Omaha, Nebraska recorded its warmest Thanksgiving on record with a high temperature of 73 degrees F (22.8 degrees C). This was also the warmest temperature ever recorded this late in the autumn season in Omaha (period of record 1871-2011). On average, October 27th is the last day of the season that is at least that warm in Omaha.
  • November 2011 was drier than normal for most of the Region. Many locations in North Dakota, South Dakota, and a swath running from southwest to northeast Nebraska received less than 25 percent of normal precipitation. According to the U.S. Drought Monitor, the ongoing lack of precipitation caused moderate drought conditions to spread into eastern North Dakota, eastern South Dakota, and northern Nebraska. Additionally, abnormally dry conditions spread across North Dakota and into parts of western South Dakota. For many locations, this autumn (September, October, and November) was one of the driest on record. One of the many locations to set records this autumn was Sioux Falls, South Dakota which only received 0.87 inches (22 mm) over the three month period. To put this amount into perspective, the normal precipitation for autumn in Sioux Falls is 6.30 inches (160 mm). The old record for driest autumn occurred in 1952 with 1.02 inches (26 mm) of precipitation (period of record 1893-2011). There were some exceptions to the dryness this month. Central Wyoming, southern and eastern Kansas, and the southeastern corner of Colorado all received at least 150 percent of normal precipitation. The precipitation was a welcome sight in the drought impacted areas of Kansas and Colorado. Heavy rains occurred November 7-8 in southern and eastern Kansas. During this time many daily precipitation records were set and, when combined with the rest of the month, the precipitation helped many locations to be ranked in the top 10 wettest Novembers on record. Topeka, Kansas received 2.98 inches (76 mm) over the two day period, which included 2.05 inches (52 mm) on the 7th alone. This amount crushed a long-standing daily precipitation record of 1.43 inches (36 mm) set in 1918 (period of record 1887-2011). By the end of the month, Topeka had received 4.66 inches (118 mm) of precipitation which was the 8th wettest November on record. It is interesting to note that on average, November is usually one of the driest months of the year; however this November was the second wettest month of 2011 in Topeka.
  • The U.S. Drought Monitor had many changes this month. Beneficial rains across southern and eastern Kansas led to one category improvements for much of the drought stricken area. Additional improvements were made in south-central Colorado as two areas of extreme drought (D3) were downgraded to severe drought (D2). Only a small area of exceptional drought remained in southwest Kansas and the far southeast corner of Colorado. Nebraska and the Dakotas all had degradations, as precipitation totals were well below normal. Abnormally dry conditions (D0) spread across southern North Dakota and into northwestern South Dakota. Moderate drought (D1) spread south through eastern Nebraska and also developed in eastern North Dakota. According to the North Dakota State Climate Office, before the introduction of D1 this month, the state had gone 115 consecutive weeks with no drought. D2 spread into northeastern Nebraska and east-central South Dakota as well. According to the U.S. Seasonal Drought Outlook conditions in portions of South Dakota, Nebraska, and northern Kansas were expected to improve, while drought conditions in other areas were expected to persist.
  • For more information, please go to the High Plains Regional Climate Center Home Page.
  • Southern Region: (Information provided by the Southern Regional Climate Center)
  • November was generally a warmer than normal month for much of the Southern Region, with most stations averaging approximate 1-3 degrees F (0.56-1.67 degrees C) above normal. The highest departures from normal occurred in Arkansas, and north central Tennessee, where many stations reported monthly average temperatures between 3 to 5 degrees F (1.67 to 2.78 degrees C) warmer than expected. Tennessee had a state average temperature of 51.10 degrees F (10.61 degrees C), which was the nineteenth warmest November on record there (1895-2011). Arkansas experienced its twenty-fifth warmest November on record (1895-2011) with an average temperature of 53.40 degrees F (11.89 degrees C). All other state averages fell within the middle two quartiles. Louisiana averaged 59.80 degrees F (15.44 degrees C) for the month, while Mississippi reported a state average temperature of 55.90 degrees F (13.28 degrees C). Texas averaged 56.90 degrees F (13.83 degrees C) for the month and Oklahoma averaged a temperature of 49.60 degrees F (9.78 degrees C).
  • The month of November was a wet month for much of the northern part of the Southern Region. Many stations in Oklahoma averaged between 150 and 300 percent of normal. This was also the case for central and northern Arkansas, and western and eastern Tennessee. For Oklahoma, it was the ninth wettest November on record (1895-2011), with a state average precipitation total of 4.87 inches (123.67 mm). Arkansas averaged 8.66 inches (219.964 mm) of precipitation, making it the eighth wettest November on record (1895-2011) there. Tennessee averaged 7.36 inches (186.94 mm), which was the seventh wettest November on record (1895-2011). Elsewhere in the southern region, conditions were generally drier than normal. The driest areas included western and southern Texas, where the majority of stations received less than half the expected precipitation. This was also the case for the Florida parishes of Louisiana and the southern most counties of Mississippi. Texas averaged only 1.24 inches (31.49 mm) of precipitation. Though it was drier than normal, it was still much wetter than in recent months. Conditions were slightly wetter in Louisiana and Mississippi, though still drier than normal. Louisiana and Mississippi reported state average precipitation totals of 3.64 inches (92.46 mm) and 3.71 inches (94.23 mm), respectively.
  • Drought conditions in the Southern Region did not change much in terms of extent, however; there were significant improvements in terms of intensity. In total, the region saw approximately a ten percent reduction in areal extent of each drought category. This equates to a one category improvement over much of the region. Exceptional drought, which last month covered over 40 percent of the region, has now been reduced to just under 30 percent. Drought conditions have been removed in western Tennessee, and much of Arkansas is now drought free. Some new moderate drought has crept into southern Mississippi, but deterioration of drought conditions this month has fortunately been minimal.
  • Similar to last month, severe weather in the Southern Region did not dominate the day to day weather pattern. On the seventh of the month, a number of tornadoes touched down in south central Oklahoma, however; there were no fatalities or injuries reported. Damage was also minimal in general. The following day, more twisters touched down in northeastern Louisiana and in eastern Texas. Some minor damage was reported, but most of it was limited to trees and power lines. On the fifteenth of the month, several tornadoes touched down in southern Louisiana and southern Mississippi. Four injuries were reported in Jones County, Mississippi when an EF2 tornado packed winds in excess of 130 miles per hour (209.21 km/hr). The storm was reported to have a path length of 12 miles (19.31 km) and a maximum swath width of 300 yards (274.32 m).
  • For more information, please go to the Southern Regional Climate Center Home Page.
  • Western Region: (Information provided by the Western Regional Climate Center)
  • Several strong, deep troughs passed through the West this month, bringing cold Arctic air and slightly below to well below normal temperatures to areas west of the Rockies. The associated storm systems, however, generally resulted in precipitation values that were below normal. In part, the trajectories of these storms leave many of them with insufficient moisture to produce typical November precipitation.
  • November’s cool temperatures west of the Rockies were punctuated with warm days in the latter half of the month due to strong ridging. Many locations saw 2-3 days with temperature departures from normal greater than +10 F (5.5 C) around the Thanksgiving holiday. Tonopah, located in southwest Nevada, recorded a monthly average temperature of 36.8 F (2.67 C), tied for 9th coolest average temperature on record. Olympia, Washington was also cooler than normal with a month average of 40.5 F (4.72 C). This is the 12th coldest November on record there, and -2.8 F (1.5 C) below its November normal.
  • East of the Rockies, temperatures were near to slightly above normal. Colorado Springs, Colorado experienced a warm November at an average temperature of 40.6 F (4.8 C). This is +4.4 F (2.4 C) above normal and the 17th warmest November on a record beginning in 1948.
  • Dry conditions dominated in the West this month. The Reno, Nevada airport tied its 7th driest November in a record beginning in 1937 with a precipitation total of 0.06 in (1.52 mm). In central Oregon, the Redmond airport station also recorded its 7th driest year on record, with 0.21 in (5.3 mm). Many eastern Oregon and Washington locations received only 50-75% of their normal precipitation amounts. Albuquerque, New Mexico had its 29th driest year on record, receiving 0.13 in (3.3 mm).
  • Pockets of above-normal precipitation appear in the usually dry Southwest due to cutoff low systems that passed through the area this month. The much-needed precipitation from these systems helped to reduce the severity of the drought in western Arizona, though severe drought persists in New Mexico. San Diego Airport (Lindbergh Field), California experienced its 5th wettest November since 1914. This station received 3.12 in (79.2 mm), well above the station mean of 1.78 in (45.2 mm). Yuma, Arizona received 0.42 in (10.7 mm), tying as the 20th wettest year in a record beginning in 1948. The airport at Rock Springs, Wyoming experienced its 4th wettest November with a total of 1.46 in (37 mm), well above the station mean of 0.52 in (13.2 mm) in a record beginning in 1948. Wyoming also experienced pockets of above normal precipitation.
  • An intense storm developed southeast of Japan on November 7th, and strengthened as it moved across the northern Pacific towards the Bering Sea and western Alaska. The storm’s center dropped close to 50 millibars (1.48 inches of mercury) in 24 hours, reaching a minimum pressure of 944 millibars (27.88 inches) at its center. Waves to 35 ft (10.7 m) and 100 mph (161 kph) winds were recorded offshore as the storm approached. Hurricane force winds and blizzard conditions affected coastal Alaska. Storm surges of up to 10 ft (3 m) affected communities along Alaska’s west coast causing flooding, some structural damage and property loss. Winds of up to 93 mph (150 kph) were recorded at some locations, and many locations along the coast reported minor wind damage and downed power lines. Many locations were without power following the storm, and a subsequent smaller storm complicated rescue efforts. An ice zone connected to land had not yet developed to reduce the impact of large waves striking the coast.
  • A trough moved into Colorado and southern Wyoming Saturday bringing strong winds and heavy precipitation to the Rockies area. Gusts at Berthoud Pass reached 113 mph/182 kph and at Pike’s Peak 109 mph/ 175 kph. Other locations reported gusts in the 80-90 mph (129-145 kph) range. Mountain storm snowfall totals ranged from 14-25 in (36-63 cm). Many road closures were in effect due to the hazardous conditions. Some locations experienced power outages, and strong winds caused small wildfires in the Foothills.
  • The Caughlin Fire ignited at approximately 12:45 am PST due to arcing power lines and spread rapidly in southwest Reno due to a strong wind event featuring gusts of 45-74 mph (72-119 kph). The low relative humidity and high speed of these winds allowed the fire to spread quickly. The fire destroyed 32 homes, burned over 2000 acres, and voluntary evacuations were posted for 10,000 people.
  • A winter storm in the Pacific Northwest complicated travel leading into the Thanksgiving holiday. Wind gusts up to 97 mph (156 kph) were recorded along the Oregon coast, and gusts up to 85 mph (136 kph) in passes and canyons. More than 10,000 people were without power at some point during the storm and one fatality was reported in Washington due to a falling tree. Many road closures were reported due to downed trees. Heavy rainfall caused flooding in western Oregon and Washington, and 1-2 ft (30-60 cm) of snow was recorded in the Cascades, northern Rockies, and northern Sierra Nevada.
  • For more information, please go to the Western Regional Climate Center Home Page.

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:


November 2011 Selected Climate Anomalies and Events MapNovember 2011 Selected Climate
Anomalies and Events Map


Global Highlights

  • The combined global land and ocean average surface temperature for November 2011 was the 12th warmest on record at 13.35°C (55.81°F), which is 0.45°C (0.81°F) above the 20th century average of 12.9°C (55.0°F). The margin of error associated with this temperature is +/- 0.07°C (0.13°F).
  • Separately, the global land surface temperature was 0.61°C (1.10°F) above the 20th century average of 5.9°C (42.6°F), making this the 16th warmest November on record. The margin of error is +/- 0.11°C (0.20°F). Warmer-than-average conditions occurred across central and eastern North America, Northern and Western Europe, northern Russia, most of China and the Middle East, southeastern Australia, and southern South America. Cooler-than-average regions included Alaska, western Canada, much of Eastern Europe, Kazakhstan, and southwestern Russia.
  • Separately, the global land surface temperature was 0.61°C (1.10°F) above the 20th century average of 5.9°C (42.6°F), making this the 16th warmest November on record. The margin of error is +/- 0.11°C (0.20°F).
  • The November global ocean surface temperature was 0.39°C (0.70°F) above the 20th century average of 15.8°C (60.4°F), making it the 12th warmest November on record. The margin of error is +/- 0.04°C (0.07°F). The warmth was most pronounced across the north central and northwest Pacific, the Labrador Sea, and portions of the mid-latitude Southern oceans..
  • The November global ocean surface temperature was 0.39°C (0.70°F) above the 20th century average of 15.8°C (60.4°F), making it the 12th warmest November on record. The margin of error is +/- 0.04°C (0.07°F).
  • The combined global land and ocean average surface temperature for the September – November period was 0.52°C (0.94°F) above the 20th century average of 14.0°C (57.1°F), making it the 12th warmest such period on record. The margin of error is +/- 0.09°C (0.16°F.
  • The September – November worldwide land surface temperature was 0.87°C (1.57°F) above the 20th century average, the seventh warmest such period on record. The margin of error is +/- 0.17°C (0.31°F).
  • The global ocean surface temperature for September – November was 0.39°C (0.70°F) above the 20th century average and was the 12th warmest such period on record. The margin of error is +/- 0.04°C (0.07°F).
  • The combined global land and ocean average surface temperature for the January – November period was 0.52°C (0.94°F) above the 20th century average of 14.0°C (57.2°F), making it the 11th warmest such period on record. The margin of error is +/- 0.09°C (0.16°F).
  • The January – November worldwide land surface temperature was 0.84°C (1.51°F) above the 20th century average — the seventh warmest such period on record. The margin of error is +/- 0.20°C (0.36°F).
  • The global ocean surface temperature for the year to date was 0.41°C (0.74°F) above the 20th century average and was the 11th warmest such period on record. The margin of error is +/- 0.04°C (0.07°F).
  • La Niña conditions continued during November 2011. According to NOAA's Climate Prediction Center, La Niña is expected to continue through the Northern Hemisphere winter 2011/12.
  • The average Arctic sea ice extent during November was 11.5 percent below average, ranking as the third smallest November extent since satellite records began in 1979. The extent was 1.3 million square kilometers (502,000 square miles) below average. This marks the 18th consecutive November and 126th consecutive month with below-average Arctic sea ice extent.
  • On the opposite pole, the November Antarctic monthly average extent was 0.5 percent below the 1979–2000 average, the 11th smallest on record. This is the first November since 2002 with below-average Antarctic ice extent.
  • Northern Hemisphere snow cover extent was much-above average during November with the fourth largest November snow cover extent in the 46-year period of record. Both the North American and Eurasian land areas had above-average snow cover extents.
  • Much of Europe experienced extreme dryness during November. Both Germany and Austria reported their driest Novembers on record. Much-wetter-than-normal conditions occurred across parts of South Asia and northeast Africa.


Introduction

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 2009 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.

Temperature anomalies for November 2011, September–November 2011, and January–November are shown on the dot maps in the following section. 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.


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Temperatures

In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. 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 November 2011 height and anomaly mapNovember 2011 and September–November 2011 height and anomaly mapSeptember–November 2011 maps—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.

November

The climate phenomenon La Niña continued through November, which helped produce cooler—although still above-average—temperatures on a global scale compared with previous months. The average temperature over land was 0.61°C (1.10°F) above the 20th century average. This marks the coolest monthly average temperature anomaly over land since February 2011 and the coolest November land temperature since 2000. However, it was the 16th warmest November since records began in 1880. Regionally, warmer-than-average conditions occurred across central and eastern North America, Northern and Western Europe, northern Russia, most of China and the Middle East, southeastern Australia, and southern South America.

The November average monthly temperature in Norway was 4.6°C (8.3°F) above average, making this month the country's warmest November since records began in 1900. The average temperature for Northern Norway was 5.3°C (9.5°F) above normal, also a new November record.

According to the UK Met Office, November 2011 was the second warmest November on record for the United Kingdom, Behind 1994, at 2.9°C (5.2°F) above normal. Provisionally, Scotland recorded its warmest November on record.

In Asia, China reported its third warmest November since national records began in 1951, according to the Beijing Climate Center. It was the warmest November on record in 12 provinces and second warmest in four provinces.

Cooler-than-average regions around the globe included Alaska, western Canada, much of Eastern Europe, Kazakhstan, and southwestern Russia. Alaska reported its sixth coolest November on record.

Land tends to absorb and release heat much faster than water. Thus, land temperatures generally fluctuate more rapidly than ocean surface temperatures and this is well illustrated by the global anomaly differences between October and November 2011. While the November land surface temperature anomaly was 0.61°C (1.10°F) and 16th warmest November on record, the October 2011 land temperature was 1.10°C (1.98°F) above average and was the second warmest October on record—a difference of 0.49°C (0.88°F). On the other hand, both the October and November global ocean temperature anomalies were 0.39°C (0.70°F), ranking 11th and 12th warmest for their respective months. In fact, the global monthly ocean temperature anomaly has remained between 0.35°C (0.63°F) and 0.47°C (0.85°F) during all of 2011 to date—a range of only 0.12°C (0.22°F).

La Niña conditions during November kept east central Pacific Ocean surface waters nearly 1°C below average for that region. Sea surface temperatures were also below average in the southern Atlantic Ocean and other parts of the mid-latitude southern oceans. It was notably warmer-than-average across the north central and north west Pacific Ocean, the Labrador Sea, and the southern Indian Ocean. As stated above, the globally averaged ocean temperature was the 12th warmest November on record, but was the coolest November since 2007. According to NOAA's Climate Prediction Center (CPC), La Niña is expected to peak during December 2011–January 2012 and continue through the Northern Hemisphere spring 2012.

Combining the monthly global land and ocean temperatures, November ranked as the 12th warmest November since records began, at 0.45°C (0.81°F) above average, making this the 26th consecutive November and 321st consecutive month with a global temperature above the 20th century average. The last month with below-average temperatures was February 1985. However, November 2011 also marks the coolest November since 2000 and the lowest above-average monthly temperature since February 2011.

November Anomaly Rank
(out of 132 years)
Records
°C °F Year(s) °C °F
Global
Land +0.61 ± 0.11 +1.10 ± 0.20 Warmest 16th 2010 +1.56 +2.81
Coolest 117th 1892 -0.98 -1.76
Ocean +0.39 ± 0.04 +0.70 ± 0.07 Warmest 12th 1997 +0.55 +0.99
Coolest 121st 1909 -0.49 -0.88
Ties: 1987
Land and Ocean +0.45 ± 0.07 +0.81 ± 0.13 Warmest 12th 2004 +0.74 +1.33
Coolest 121st 1907 -0.51 -0.92
Northern Hemisphere
Land +0.57 ± 0.11 +1.03 ± 0.20 Warmest 24th 2010 +1.99 +3.58
Coolest 109th 1892 -1.24 -2.23
Ocean +0.42 ± 0.04 +0.76 ± 0.07 Warmest 12th 2006 +0.66 +1.19
Coolest 121st -0.52 -0.94 0.05
Land and Ocean +0.47 ± 0.08 +0.85 ± 0.14 Warmest 15th 2010 +1.02 +1.84
Coolest 118th 1892 -0.75 -1.35
Southern Hemisphere
Land +0.72 ± 0.11 +1.30 ± 0.20 Warmest 11th 2009 +1.18 +2.12
Coolest 122nd 1917 -0.90 -1.62
Ties: 1995
Ocean +0.38 ± 0.04 +0.68 ± 0.07 Warmest 15th 1997 +0.57 +1.03
Coolest 118th 1910 -0.45 -0.81
Ties: 1979
Land and Ocean +0.44 ± 0.06 +0.79 ± 0.11 Warmest 11th 2009 +0.64 +1.15
Coolest 122nd 1910 -0.49 -0.88

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

Season (September–November)

La Niña conditions were present during all three Northern Hemisphere autumn (Southern Hemisphere spring) months. Over land, temperatures were notably above normal across most of the Northern Hemisphere higher latitudes, including most of Canada, Northern Europe, and most of Russia. It was cooler than normal in much of the Middle East and part of eastern Russia. The November land temperature was 0.88°C (1.58°F) above average, making this the seventh warmest global land November on record.

Norway recorded its warmest autumn since records began in 1900. The average temperature was 3.0°C (5.4°F) above average, topping the previous record set in 2000 of 2.8°C (5.0°F) above average. It was also Finland's warmest autumn since 1938.

It was the second warmest autumn on record for the United Kingdom in more than a century, with temperatures 2.1°C (3.8°F) above average. November 2006 was the warmest at 2.3°C (4.1°F) above average. In Central England, autumn temperatures were the second warmest in at least 350 years.

While the nationally averaged November temperature for Austria was only about 1°C above normal, the average temperature at high elevation stations was 2.6°C above average, giving this region the second warmest November in the country's 161-year period of record. The warmest autumn in the high-elevation alpine regions occurred in 2006, with temperatures 3.2°C above average, according to Zentralanstalt für Meteorologie und Geodynamik (ZAMG), Austria's National Meteorological Service.

It was the 12th warmest September–November across the global oceans. Sea surface temperatures were warmer than average across the north central and north west Pacific Ocean and parts of the mid-latitude southern oceans. Ocean temperatures were cooler than average in the east central Pacific Ocean, where La Niña conditions were observed, as well as the north east Pacific, the southern Atlantic Ocean, and parts of the mid-latitude southern oceans.

The combined global land and ocean surface temperature for September–November was the 11th warmest such period on record and the coolest since 2007, at 0.53°C (0.95°F) above the 20th century average.

September–November Anomaly Rank
(out of 132 years)
Records
°C °F Year(s) °C °F
Global
Land +0.87 ± 0.17 +1.57 ± 0.31 Warmest 7th 2005 +1.17 +2.11
Coolest 126th 1912 -0.70 -1.26
Ocean +0.39 ± 0.04 +0.70 ± 0.07 Warmest 12th 1997, 2003 +0.56 +1.01
Coolest 121st 1909 -0.46 -0.83
Land and Ocean +0.52 ± 0.09 +0.94 ± 0.16 Warmest 12th 2005 +0.68 +1.22
Coolest 121st 1912 -0.50 -0.90
Northern Hemisphere
Land +0.93 ± 0.18 +1.67 ± 0.32 Warmest 6th 2005 +1.32 +2.38
Coolest 127th 1912 -0.87 -1.57
Ties: 2001
Ocean +0.42 ± 0.04 +0.76 ± 0.07 Warmest 11th 2006 +0.65 +1.17
Coolest 122nd 1912 -0.52 -0.94
Ties: 1998
Land and Ocean +0.61 ± 0.11 +1.10 ± 0.20 Warmest 10th 2005 +0.85 +1.53
Coolest 123rd 1912 -0.65 -1.17
Southern Hemisphere
Land +0.73 ± 0.14 +1.31 ± 0.25 Warmest 10th 2009 +0.99 +1.78
Coolest 123rd 1917 -0.61 -1.10
Ocean +0.39 ± 0.04 +0.70 ± 0.07 Warmest 13th 1997 +0.58 +1.04
Coolest 120th -0.43 -0.77 0.06
Ties: 2000
Land and Ocean +0.44 ± 0.07 +0.79 ± 0.13 Warmest 11th 1997 +0.63 +1.13
Coolest 122nd 1910 -0.45 -0.81
Ties: 2001

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

Year-to-date (January–November)

La Niña conditions were present in the east central Pacific Ocean during 2011 to date, with the exception of April through July, when ENSO-neutral conditions prevailed. The January–November 2011 global combined land and ocean temperature anomaly of 0.53°C (0.95°F) was the 11th warmest such period on record but the coolest since 2008 (0.50°C / 0.90°F), which was also a La Niña year. Separately, the January–November global land and global ocean temperatures ranked as the 7th and 11th warmest such periods, respectively.

January–November Anomaly Rank
(out of 132 years)
Records
°C °F Year(s) °C °F
Global
Land +0.84 ± 0.20 +1.51 ± 0.36 Warmest 7th 2010 +1.07 +1.93
Coolest 126th -0.56 -1.01 0.09
Ocean +0.41 ± 0.03 +0.74 ± 0.05 Warmest 11th 1998 +0.53 +0.95
Coolest 122nd 1911 -0.46 -0.83
Ties: 2007
Land and Ocean +0.52 ± 0.09 +0.94 ± 0.16 Warmest 11th 2010 +0.66 +1.19
Coolest 122nd 1911 -0.43 -0.77
Northern Hemisphere
Land +0.93 ± 0.25 +1.67 ± 0.45 Warmest 5th 2007 +1.20 +2.16
Coolest 128th 1884 -0.68 -1.22
Ocean +0.40 ± 0.04 +0.72 ± 0.07 Warmest 12th 2005 +0.56 +1.01
Coolest 121st 1910 -0.47 -0.85
Ties: 2008
Land and Ocean +0.60 ± 0.14 +1.08 ± 0.25 Warmest 11th 2010 +0.78 +1.40
Coolest 122nd -0.43 -0.77 0.06
Southern Hemisphere
Land +0.60 ± 0.12 +1.08 ± 0.22 Warmest 10th 2005 +0.90 +1.62
Coolest 123rd 1917 -0.75 -1.35
Ties: 1987
Ocean +0.42 ± 0.03 +0.76 ± 0.05 Warmest 11th 1998 +0.55 +0.99
Coolest 122nd 1911 -0.49 -0.88
Land and Ocean +0.45 ± 0.06 +0.81 ± 0.11 Warmest 11th 1998 +0.60 +1.08
Coolest 122nd 1911 -0.50 -0.90
Ties: 2007

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.

November

Much of Europe experienced extreme dryness during November. Germany reported its driest November since records began in 1881, measuring just 61 percent of its average monthly rainfall. Several locations recorded no measureable rainfall. Austria also had its driest November since national records began in 1858, with just 2 percent of average rainfall for the month. The second driest November was recorded in 1920, with 14 percent of average monthly rainfall.

Much-wetter-than-normal conditions occurred across parts of South Asia and northeast Africa. Tropical Depression Keila brought very heavy precipitation to the Arabian Peninsula at the beginning of the month. November rainfall across China was, on average, 57 percent above normal, marking the wettest November since 1983 for the country. It was the wettest November on record for the provinces of Shanxi, Shaanxi, Gansu, Ningxia, and Fujian.

September–November

The areas with the wettest anomalies during September–November (Northern Hemisphere fall; Southern Hemisphere spring) included part of southwestern Asia and the Middle East, northern China, and western Australia. The driest anomalies during this period were observed over much of Europe, the central United States, part of northeast Asia, and east central Australia.

The United Kingdom saw large variations in precipitation during autumn. According to the UK Met Office, it was the second wettest September–November on record in Northern Ireland. In contrast, it was the driest such period since 1978 in the Midlands, and the driest since 1985 in East Anglia and southeast England.

Year-to-date (January–November)

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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 2 December 2011


November 18thOne of the worst wildfires in Nevada's history breaks out in Reno read more November 15th–19ththRecord cold temperatures chill Fairbanks, Alaska read more NovemberthFlooding continues in Thailand read more early NovemberthFlooding kills seven people in northwest Italy read more November 5thMudslide kills at least 38 people in Colombia read more November 5th&ndash15thTorrential rains hit Kenya and Uganda read more November 8th–9thPowerful storm strikes western Alaska read more November 16thTornadoes kill six people in southeast United States read more November Texas Christmas tree production harmed by ongoing drought read more November thMexico experiences worst drought in seven decades read more November 18thThe Midlands in England has its driest 12-month period in at least a century read more



Drought conditions

Fire in southwest Reno, Nevada on 18 November 2011
Fire in Reno, Nevada
18 November 2011
Image Credit: NOAA

One of the worst fires in Nevada's history broke out in southwest Reno on November 18th. Fanned by winds gusting to more than 70 mph (113 km/hr), flames up to 100 feet (30 meters) in height forced almost 10,000 people to evacuate their homes and destroyed 32 houses. The fire was extinguished by the 20th and in total, 1,953 acres (790 hectares) were burned. According to the Reno fire chief, at times the fire spread at 20–30 mph (32–48 km/hr). The fire was particularly difficult to fight due to the combination of the high winds, rocky terrain, and accessibility. One fatality was blamed on the blaze.

The ongoing historic drought in Texas and Oklahoma took its toll on local Christmas tree farms in November. Thousands of trees were killed due to either lack of rainfall and exposure to extreme heat or from wildfires that scorched farmland earlier in the year. Growers also had difficulty keeping young saplings alive, which could affect Christmas tree production in future years. For the year-to-date (January–October), Texas received only 11 inches (279 mm) of rain. This is less than half of the average amount (24 inches; 610 mm) that typically falls during the same period. Oklahoma experienced its third driest January–October on record, receiving less than 19 inches (483 mm) of rain, compared with its average of 30 inches (762 mm).

Conditions were also poor south of Texas. By late November, Mexico was experiencing its driest year in seven decades, according to an official at the Ministry of Agricultural and Rural Development. Nearly 70 percent of the country was affected, with the northern states of Coahuila, San Luis Potosi, Sonora, Tamaulipas and Zacatecas especially hard hit. An estimated 2.5 million people across 1,500 communities lacked drinking water (water was trucked in). Additionally, 2.2 million acres (900,000 hectares) of cropland was destroyed and an estimated 450,000 livestock were lost due to the harsh drought conditions. Forecasts for corn production were cut twice by the government, due to the drought and a cold snap at the beginning of the year. Mexico is one of the top five corn producers in the world.

Parts of England were placed on drought alert as the Midlands had its driest 12-month period since records began in 1910. Residints in Cambridgeshire, South Lincolnshire and Northamptonshire were requested to conserve water. In Southern England, a 10-mile stretch of the Kennet and Avon Canal was closed when water levels reached the lowest point in 90 years.

Please visit NCDC's Drought and Wildfire pages for more detailed U.S. information.

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Extreme Temperatures

Temperatures were more frigid than usual in Fairbanks, Alaska during the third week of November. According to NOAA's National Climatic Data Center U.S. Records, low minimum temperature records were set every day from the 15th to the 19th at Fairbanks International Airport. The coldest temperature of the week at the airport was recorded on the 17th, as temperatures dropped to -41°F (-41°C), breaking the previous record of -39°F (-39°C) for that date set in 1969. It was even colder at North Pole, Alaska that day, where temperatures plunged to -49°F (-45°C), breaking its previous daily record of -46°F (-47°C), also set in 1969.

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Heavy rainfall and flooding

Flooded highway in Bangkok suburb on 19 November 2011
Flooded Highway, Bangkok, Thailand
19 November 2011
Image Credit: Getty Images

Thailand's flooding, which began in July due to a combination of unusually heavy monsoon rains and tropical storm systems, continued into November. As of November 20th, 17 of the country's 76 provinces were still affected by the floodwaters. At least 602 deaths have been blamed on the flooding over the past four months. The Thai government estimated that 2.9 million people were impacted by the floods. Nearby, Vietnam and Cambodia were also hit hard by the rains. An estimated 500,000 Vietnamese were impacted, and according to the Global Disaster Alert and Coordination System, at least 100 people were killed in the country as torrential downpours fell over several central provinces and over the country's southern Mekong Delta. At least 250 people also lost their lives in Cambodia.


Flooded street in Genoa, Italy on 4 November
Flooded Steet, Genoa, Italy
4 November 2011
Image Credit: AP

Heavy rains during the last week in October and first week in November culminated in fresh flooding in northwest Italy. At least seven people in Naples and Genoa were killed. In the city of Turin, schools were closed on November 7th and thousands of residents were told to evacuate as the River Po—Italy's longest river—rose 13 feet (4 meters). The prime minister said that unauthorized building due to lax local construction laws exacerbated the flooding problems.

In the midst of "one of its worst rainy seasons in decades", a mudslide in Colombia's western city of Manizales killed at least 44 people on November 5th and left at least 19 missing. In total, about 250,000 people were affected by the rains and subsequent floods and landslides. Meteorologists were expecting above-average rainfall to continue through November and December.

In eastern Africa, torrential rains fell over Uganda and Kenya from November 9th to 15th. In Kenya, at least four people were killed in the Kolowa region of the Rift Valley and a total of 10,000 residents were displaced. On the 12th, heavy rains fell for six hours over Bute town in the northeastern reion. The Bute ward councillor said that rainfall of this magnitude was the highest since 1974, according to the Global Disaster Alert and Coordination System. At least 15,000 people were displaced in Uganda. No fatalities were reported.

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Severe Storms

GOES satellite imagery of storm system on 8 November 2011
Alaskan Storm Satellite Imagery
8 November 2011

A powerful storm struck Alaska's western coast on November 8th–9th, the strongest to impact the region since 1974. Hurricane force winds brought gusts as high as 89 mph (143 km/hr) to Wales, Alaska, which is located at the western tip of the Seward Peninsula, forming the U.S. side of the Bering Strait. A storm surge of 8.6 feet (2.6 meters) hit Nome, the largest town in the path of the storm, with a population of about 3,600. The surge overtopped a sea wall, washing heavy equipment and cleaning supplies out to sea. Otherwise, damage was generally minor, limited mainly to blown out windows and battered roofs. No injuries were reported. According to a media report, Alaska's Division of Homeland Security and Emergency Management noted that "the state benefitted from accurate advance forecasts of the storm and good coordination among local, state and federal agencies".


U.S. map of NOAA's Storm Prediction Center storm reports on 16 November 2011
NOAA's Storm Prediction Center
Storm Reports
16 November 2011

A cold front stretching from the Gulf of Mexico to the Northeast United States collided with a warm air mass on November 16th, creating severe storms that spawned tornadoes across several states. NOAA's Storm Prediction Center listed 22 preliminary tornado reports—including two EF-2 twisters—in Alabama, Georgia, South Carolina, North Carolina, and Virginia. Six people were killed across the region and dozens of homes and buildings sustained damages.

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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.

Northern hemisphere snow cover anomalies
November Snow Cover Anoamlies
Source: Rutgers Global Snow Lab
and NSIDC

During the month of November, several strong low pressure systems moved through the central part of the country, bringing wet conditions to much of the Ohio Valley and stretching into the Southern Plains. Temperatures were warmer than average for most of the East, with the warmest temperature anomalies occurring across the Ohio Valley and into the Northeast. These weather conditions did not allow much snowfall to accumulate east of the Mississippi River, limiting the monthly snow cover extent. Several of the storms dropped heavy snow over the intermountain West, the only region of the country to have snow cover extent exceeding the 1971-2000 average, according to data from the Rutgers Global Snow Lab.

At the beginning of November, 4.4 percent of the contiguous U.S. had snow on the ground, according to NOAA's National Snow Analyses. Snow cover was limited to the high terrain of the West, and across the Northeast, with snow lingering from the unprecedented storm at the end of October. The percent area of the U.S. with snow cover grew to 10.1 percent by the end of November. Snow was present on the ground across the high terrain of the west, the western Great Lakes, across the Midwest and along the spine of the Appalachians. A small area of snow was also on the ground in the Mid-Mississippi Valley, where an early season snow storm dropped several inches of snow from Missouri into Mississippi on November 29th.

Synoptic Discussion

Note: This Synoptic Discussion describes recent weather events and climate anomalies in relation to the phenomena that cause the weather. These phenomena include the jet stream, fronts and low pressure systems that bring precipitation, high pressure systems that bring dry weather, and the mechanisms which control these features — such as El Niño, La Niña, and other oceanic and atmospheric drivers (PNA, NAO, AO, and others). The report may contain more technical language than other components of the State of the Climate series.


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.


Synoptic Discussion

Upper-level circulation pattern and anomalies averaged for November 2011
Upper-level circulation pattern and anomalies averaged for November 2011.

A vigorous weather patternweather pattern dominated the contiguous United States during November 2011. Several strong upper-level low pressure systems, typical of the fall transition season, brought areas of rain and snow with cold temperatures, while southerly winds swept warmer-than-normal air ahead of the storm systems. Snow cover expanded and contracted with the winter storms, reaching 28 percent of the contiguous U.S. by the 21st. Nearly 1100 daily high temperature records were tied or broken during the month, and over 1600 warmest minimum temperature records occurred. Fewer cool records occurred, with nearly 600 lowest minimum temperature records and over 700 coolest maximum temperature records tied or broken. Despite the vigorous circulation, tornado activity was near average for the month, but the weather systems brought beneficial precipitation to the drought areas with the national drought footprint decreasing to about 29.3 percent in moderate to exceptional drought.

During November, warmer-than-average temperatures dominated the eastern half of the country with the warmest temperature anomalies occurring across the Midwest, Mid-Atlantic, and Northeast. Thirteen states from Indiana to Maine had November temperatures ranking among their ten warmest. Cooler-than-average temperatures were present across the West, with California, Idaho, Nevada, Oregon, Washington, and Wyoming having November temperatures cooler than average. Precipitation was also variable across the nation with wetter-than-normal conditions across parts of the Southern Plains and across the Ohio Valley. Drier-than-average conditions were present across the West, the upper Midwest, New England, Texas, and Florida. Minnesota had its ninth driest November on record. When averaged together, the mixture of temperature and precipitation extremes gave the U.S. the 25th warmest and 37th wettest November in the 117-year record.

Cold fronts and low pressure systems moving in the storm track flow are influenced by the broadscale atmospheric circulation. Four such large-scale atmospheric circulation drivers were potentially influential during November:

Map of monthly temperature anomalies Map of monthly precipitation anomalies

The pattern of observed temperature anomalies for November 2011 and the last three months (September-November) corresponds to the La Niña and AO in the Northern Plains to Great Lakes, and PNA in the Northwest. The November 2011 and September-November 2011 precipitation patterns are a reasonable match for the La Niña pattern across much of the West and the La Niña and AO patterns from the Northern Plains to western Great Lakes, and the NAO pattern for the Ohio Valley.

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, the count of tornado reports during November 2011 — 60 — was near the 1991-2010 average of 58. The tornado activity during the month of November was mostly confined to the southern tier of the country. The preliminary tornado reports during November continued to push the annual tornado count upwards, with the 2011 tornado count encroaching on the annual record of 1,817 set in 2004. During the January-November period, 1,543 tornadoes have been confirmed with 146 preliminary tornado reports still pending. This ranks the January-November 2011 period among the top three most active such periods since the modern tornado record began in 1950.

OK Radar image 7 November
Radar Loop of Oklahoma Tornado Outbreak
7-8 November 2011
Source:NWS

On November 7th, an EF-4 tornado was confirmed near Tipton, Oklahoma. The tornado was associated with a supercell thunderstorm which spawned five other tornadoes the same day across southwestern Oklahoma. The tornado was a rarity for the United States. This was the first observed EF-4 to hit Oklahoma during the month of November, and only the 22nd EF-4 or stronger tornado on record to ever touch down anywhere in the country during November.

U.S. Severe Weather Reports 16 November 2011
Severe Weather Reports 16 November 2011
Source:SPC

The most significant tornado outbreak during November 2011 occurred on the 15th and 16th of the month when there were 29 preliminary tornado reports across the South and Southeast. A strong low pressure system moving across the center of the country brought a strong cold front through the southeastern United States. As the cold front moved through, it spawned severe weather from Texas to Virginia. There were five fatalities reported, associated with two tornadoes in the Carolinas.

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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.

North Indian Basin

Keila
Tropical Storm Keila Satellite Image
Keila Track
Tropical Storm Keila Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Keila
Cyclogenesis Date 11/02
Cyclolysis Date 11/02
Highest Saffir-Simpson Category TS
Maximum 6-hr Sustained Wind 40 mph (35 kt or 65 km/h)
Min Pressure 996 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) .3675 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths 14
*The (ACE) Index calculations are based on preliminary data.

Five
Tropical Storm Five Satellite Image
Five Track
Tropical Storm Five Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Five
Cyclogenesis Date 11/26
Cyclolysis Date 11/30
Highest Saffir-Simpson Category TS
Maximum 6-hr Sustained Wind 40 mph (35 kt or 65 km/h)
Min Pressure 998 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 1.8375 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths 19
*The (ACE) Index calculations are based on preliminary data.

Atlantic Basin

During the first week of November, an extratropical low pressure system departed the coast of South Carolina and settled several hundred miles southwest of Bermuda. On November 8, the disturbance attained gale-force winds of 45 mph (75 km/h); however, due to the presence of a cold core, the cyclone was named Subtropical Storm Sean. Upon disassociating from its parent upper-level low, the storm was declared fully tropical hours later. Tracking northeast, its center passed within 80 miles (180 km) of Bermuda, then continued out to sea. By November 12, the storm had transitioned to extratropical and was absorbed by a cold front in the northern Atlantic. Overall storm impacts included precipitation amounts of less than 1 inch (25.4 mm) in Bermuda as well as one storm surge-related drowning near Florida’s east coast. On average, a named storm forms in the Atlantic basin in November once every other year.

Sean
Tropical Storm Sean Satellite Image
Sean Track
Tropical Storm Sean Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Sean
Cyclogenesis Date 11/08
Cyclolysis Date 11/12
Highest Saffir-Simpson Category TS
Maximum 6-hr Sustained Wind 63 mph (55 kt or 102 km/h)
Min Pressure 983 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 3.7225 x 104
Landfall Information (date, location and sustained winds) N/A
Deaths 0
*The (ACE) Index calculations are based on preliminary data.


East North Pacific Basin

A rarity, both for its late-season (November 1 or later) occurrence and its affiliation with wave-like motions other than African tropical waves, Kenneth formed as a tropical depression on November 18. Benefiting from unseasonably low wind shear and unseasonably warm ocean temperatures of 27 degrees C (80.6 degrees F), the storm rapidly intensified to a Category 1 and Category 2 hurricane on November 21. Near dawn on the following day, Kenneth became a Category 4 hurricane with winds of 145 mph (230 km/h) – its peak intensity. As it traversed colder waters, the storm downgraded to tropical storm strength less than 24 hours later. It tracked westward out to sea for the length of its lifespan posing no threat to land areas. By November 25, Kenneth weakened to a remnant low and was later absorbed by a stationary system near the eastern border of the Central Pacific. On average, a hurricane forms during November in the Eastern Pacific basin once every 10 years. Kenneth is not only the latest occurring major hurricane since the start of the satellite era (1971), but also the strongest late-season tropical cyclone on record in the Eastern Pacific.

Kenneth
Tropical Storm Kenneth Satellite Image
Kenneth Track
Tropical Storm Kenneth Forecast Track


Safir Simpson Color Legend for Track Map from Unisys
Saffir-Simpson Scale Color Legend
Tropical Cyclone Summary
Tropical Cyclone Kenneth
Cyclogenesis Date 11/20
Cyclolysis Date 11/25
Highest Saffir-Simpson Category Cat 4
Maximum 6-hr Sustained Wind 144 mph (125 kt or 232 km/h)
Min Pressure 943 mbar
Accumulated Cyclone Energy (ACE*) Index (kt2) 11.0225 x 104
Landfall Information (date, location and sustained winds)
Deaths 0
*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 December 2011
Contents Of This Report:
Map showing Palmer Z Index

National Drought Overview

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Detailed Drought Discussion

Overview

November 2011 was warmer and wetter than average (25th warmest and 37th wettest, based on data back to 1895) when weather conditions are averaged across the country. But this reflected regional extremes in both monthly temperature and precipitation, as well as weekly regional patterns of temperature anomalies (weeks 1, 2, 3, 4) and precipitation anomalies (weeks 1, 2, 3, 4). Drought areas contracted slightly in the parts of the Central Plains and Mid-Mississippi Valley drought areas which received beneficial precipitation, but the precipitation had little effect on deficits that have accumulated over the last 12 months in the Plains and last 3 to 6 months in the Mid-Mississippi Valley. Drier-than-normal weather during November expanded drought in the Upper Mississippi Valley and Northern Plains, but the drought areas remained the same or contracted slightly in the Southeast and West. Rainfall over parts of Hawaii shrank the moderate to extreme drought area from 66 percent last month to 54 percent this month. Nationally, the moderate-to-exceptional drought footprint decreased to about 25 percent of the country and the percentage in the worst category (D4, exceptional drought) dropped to about 5 percent.

U.S. Drought Monitor map from November 29, 2011
The U.S. Drought Monitor drought map valid November 1, 2011.

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


Palmer Drought Index

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.

Palmer Z Index map Palmer Hydrological Drought Index map

As seen on the November 2011 Palmer Z Index map, low precipitation led to short-term drought across the Upper Mississippi Valley, New England, and parts of the Northwest and Southern Plains this month. Wet conditions are evident on the Z Index map across the Ohio Valley to parts of the Central to Southern Plains. Compared with the October 2011 PHDI map, the November 2011 PHDI map indicates that drought conditions intensified in the Upper Mississippi Valley but decreased in intensity in parts of the Central Plains and Lower Mississippi Valley; wet conditions decreased in parts of the West and northern New England; and wet conditions increased in the Ohio Valley. The November 2011 PHDI map also reflects the long-term nature of the drought conditions. The Z Index and PHDI maps in combination show that precipitation brought relief to parts of the Central and Southern Plains drought area, near normal November moisture conditions occurred over much of the Southeast drought area, and moisture conditions further dried in parts of the Northwest and New England; but for the Ohio Valley, Upper Mississippi Valley, and extreme Southern Plains — precipitation fell where it was already wet and it was drier than normal over the existing drought areas.


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.

1-month Standardized Precipitation Index 3-month Standardized Precipitation Index 6-month Standardized Precipitation Index

Dryness is evident in the Northern Plains and northern New England during November (1 month map), the Central Gulf Coast states and the climate divisions along the Rio Grande-Mexico border for the last 2 months, the Midwest to Upper Mississippi Valley, and the northwestern third of the country, at 1 to 6 months, the northwestern Great Lakes at 9 to 24 months, the Southwest to Southern Plains from 3 to 24 months, and the Southeast from 6 to 24 months. The Upper Mississippi Valley dryness is most severe at 3 months, and the Southwest to Southern Plains dryness is most severe at 6 to 12 months. Wet conditions caused by several frontal systems can be seen along the Central Plains to Ohio Valley at 1 to 2 months, spring and summer flooding are evident in the wetness from the Ohio Valley to Northeast at 6 to 9 months, and last winter's above-normal precipitation is still evident across the West at 12 months. This illustrates the persistence of the dry and wet areas.


9-month Standardized Precipitation Index 12-month Standardized Precipitation Index 24-month Standardized Precipitation Index

Agricultural and Hydrological Indices and Impacts

NWS/CPC Leaky Bucket soil moisture percentiles
NWS/CPC Leaky Bucket soil moisture percentiles
USGS monthly streamflow percentiles
USGS monthly streamflow percentiles

Drought conditions were reflected in numerous agricultural, hydrological, and other meteorological indicators, both observed and modeled. Across the drought areas of the Southeast, streamflows were low and many groundwater well stations were at or near record low levels for this time of year. Low streamflows also characterized the drought areas of the Southwest and Southern Plains, where soil moisture was depleted, water restrictions were implemented in many communities, and pastures, rangeland, crops, and natural vegetation were ravaged. Streamflow was low and soils dry in the Upper Mississippi and Western Great Lakes drought areas as well. Parts of the Southwest, Great Plains, and Upper Mississippi Valley had few, if any, days with precipitation in November. This summary is based on the following observed and modeled indicators:

hydrological:

USGS groundwater map
USGS groundwater map.

agricultural:

VegDRI (Vegetation Drought Response Index) map
VegDRI (Vegetation Drought Response Index) map.

meteorological:

Map of maximum consecutive dry days
Map of maximum consecutive dry days.

Regional Discussion

November 2011 was a drier-than-normal month for many stations in the Hawaiian Islands. Above-normal rainfall on some islands shrank the percent of the state in moderate to extreme drought from 66 percent last month to 54 percent this month, but longer-term conditions remained drier than normal (last 2, 3, 6, 12, 24, 36 months), especially for the southern islands. November SPI values were consistently in the drought category for many locations, especially in Maui County, but streamflow was generally near normal.

Most stations in central and southern Alaska were drier than normal this month, continuing a trend which has dominated the last 2 to 3 months. The dryness is evident over the last three years (6, 12, 24, 36 months). Modeled soil moisture was drier than normal and November 30th snow water content (for stations and basinwide) was below normal at the interior locations, but some coastal locations were wetter than normal. Statewide, Alaska had the 41st driest November and 47th wettest autumn (September-November) in the 1918-2011 record, and there was no drought or abnormal dryness indicated on the November 29th USDM.

The southeastern third and northwestern corner of Puerto Rico were drier than normal during November. The dryness in the southeast was very evident at 2 months and still noticeable at 3 months, but disappears at longer time scales (6 months, and year to date). With streamflow near average, the November 29th USDM map had no drought or abnormally dry areas on the island.

State precipitation ranks, November 2011 State precipitation ranks, December 2010-November 2011

On a statewide basis, November 2011 ranked in the top ten driest Novembers for Minnesota with two other states close behind (Maine at 11th driest and North Dakota at 12th driest). Nine other states (in New England, the Northern and Southern Plains, Southeast, and Far West) ranked in the driest third of the historical record. For the last three months (September-November 2011), prolonged dryness in the Upper Mississippi Valley ranked Minnesota third driest, South Dakota 13th driest, and Iowa 14th driest, while Texas ranked 13th driest and five other states (in the Upper Midwest, Central Great Plains, and Northwest) ranked in the driest third category. The dryness in the Southern Plains and Southeast lowered the ranks at longer time scales, with Texas ranking second driest, Georgia 11th driest, and New Mexico 12th driest, for June-November; thirteen other states (in the Southeast, Central Plains to western Great Lakes, and Northwest) ranked in the driest third category. Five states (New Mexico, Texas, Oklahoma, Louisiana, and Georgia) were in the top ten driest category for January-November and the last 12 months (December 2010-November 2011), with South Carolina close behind at 11th driest for both periods. Record dryness occurred for Texas at several time scales. Widespread and persistent dryness gave the Rio Grande and Texas Gulf Coast river basins the driest December-November in the 1895-2011 record.

Rio Grande River Basin Precipitation, December-November, 1895-2011 Texas Gulf Coast Basin Precipitation, December-November, 1895-2011

During November, moderate to exceptional drought contracted to 72 percent of the South region, 42 percent of the Southeast region, 15 percent of the Midwest region, and 54 percent of Hawaii. It stayed about the same at 23 percent of the High Plains region and 19 percent of the West. Beneficial rains during the month shrank the worst drought category (D4, exceptional drought) in the South region from 42 percent last month to 29 percent this month, the second month in a row with decreasing exceptional drought area. Exceptional drought shrank from 65 percent to 53 percent for Texas, from 43 percent to 10 percent for Oklahoma, and from 26 percent to 18 percent for New Mexico. It dropped from 9 percent last month to 6 percent this month for the contiguous United States.

On a more localized basis, record dryness did not occur in any climate division during November, but record dryness did occur at a few climate divisions in the Upper Midwest and Deep South Texas during autumn (September-November) and in the Southern Plains at longer time scales (June-November, January-November, and December-November).

PHDI for Louisiana climate division 1 (Northwest), January 1900-November 2011
PHDI for Louisiana climate division 1 (Northwest), January 1900-November 2011.

The prolonged and intense drought conditions caused a rapid intensification of the PHDI, with several climate divisions reaching record dry PHDI values during the summer. Beneficial October and November rains backed off the PHDI values to only near-record intensity. While no longer record dry, the November 2011 PHDI values are still drier than any pre-2011 values for five climate divisions: northwest Louisiana (division 1), New Mexico's Southeastern Plains (division 7), and the Trans Pecos (division 5), High Plains (division 1), and East division (4) in Texas. These climate divisions mostly fall within the drainage basins of two river systems, the Rio Grande and the Texas Gulf Coast Basin.

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, based on the Palmer Drought Index.

A large part of the West was drier than normal during November. The November and October precipitation patterns resulted in a dry start to the water year (October through the following September) for large areas from central Washington to central California and Nevada, as well as southern Arizona and New Mexico. Water-year precipitation was above normal across parts of the Northern and Central Rockies. This is evident in both low elevation and high elevation (SNOTEL) station data. Although total precipitation was above normal, more fell as rain than snow, resulting in below-normal snowpack moisture in many high elevation basins. The previous water year (October 2010-September 2011) left the West with moist conditions in the north and dry conditions in the south, as reflected in modeled soil moisture, PHDI, and streamflow, although conditions were drying out in recent months. An analysis of early data by the USDA indicated that reservoir levels were, on average, below normal in New Mexico but near to above average in most other western states. According to the USDM, 19 percent of the West was experiencing moderate to exceptional drought at the end of November, about the same as October, while the Palmer Drought Index statistic was about 14 percent, a decrease of about 1 percent. When the statistics for the Arizona-New Mexico-Colorado drought area (the Southwest drought area) are aggregated, the percent area in moderate to exceptional (USDM categories) drought has fluctuated between 60 and 70 percent for the last nine months. The percent area in the exceptional and extreme to exceptional categories steadily increased from March to June then leveled off with monsoon showers in July, then decreased slightly in August. The extreme to exceptional category has held steady at about 32 percent since then, while the exceptional drought area has decreased to about 6 percent at the end of this month.

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

SoutheastSouthMidwestNortheastHigh Plains
WestUpper Colorado River BasinPacific Islands

As noted by the Southeast Regional Climate Center, as in October, precipitation was highly variable across the Southeast during November. Monthly totals were between 150 and 200 percent of normal across northern portions of Alabama, Georgia, and South Carolina, and across western portions of North Carolina and Virginia. The driest locations in the Southeast were found across the southern two-thirds of Florida, where monthly precipitation totals were between 5 and 25 percent of normal. Daytona Beach, Florida recorded just 0.06 inch (1.5 mm) of precipitation, making it the second driest November in a record extending back to 1922. Elsewhere across the region, monthly precipitation was between 50 and 75 percent of normal, including the eastern slopes and interior mountains of Puerto Rico. Precipitation across the rest of the island was between 150 and 300 percent of normal. Mean temperatures in November were near normal across most of the region. The cold spell that occurred in the middle of the month resulted in trace amounts of snowfall across the higher elevations of western North Carolina and Virginia. Several locations across the interior of the region reported measurable snowfall from the 28th to the 30th of the month as an area of low pressure tracked through the Tennessee and Ohio River Valleys. Up to 3 inches (76.2 mm) of snow was reported in northern Alabama and western North Carolina, while Caesar's Head in northwestern South Carolina recorded just its fourth measurable November snowfall ever with 1 inch (25.4 mm) on the 30th of the month.

For the second consecutive month, there were very few changes to the USDM across the Southeast region. By the end of November, more than half of the region was classified as being in drought, with nearly two-thirds of Georgia still classified as being in extreme drought. At one point during the month, the water level at Lake Lanier in northern Georgia was dropping at a rate of one foot (304.8 mm) per week. According to the North Carolina State Climate Office, adequate topsoil moisture conditions aided in the successful planting of winter grains. In contrast, the Florida State Climate Office reported that the cold spell near the middle of the month damaged vegetable crops across the Florida Panhandle, while warm temperatures and dry weather increased disease pressures to crops in parts of south Florida.

As explained by the Southern Regional Climate Center, November was generally a warmer-than-normal month for much of the Southern region and a wet month for much of the northern part of the region. Many stations in Oklahoma averaged between 150 and 300 percent of normal precipitation. This was also the case for central and northern Arkansas, and western and eastern Tennessee. For Oklahoma, it was the ninth wettest November on record (1895-2011), with a state average precipitation total of 4.87 inches (123.67 mm). Arkansas averaged 8.66 inches (219.964 mm) of precipitation, making it the eighth wettest November on record (1895-2011) there. Tennessee averaged 7.36 inches (186.94 mm), which was the seventh wettest November on record (1895-2011). Elsewhere in the Southern region, conditions were generally drier than normal. The driest areas included western and southern Texas, where the majority of stations received less than half the expected precipitation. This was also the case for the Florida parishes of Louisiana and the southern-most counties of Mississippi. Texas averaged only 1.24 inches (31.49 mm) of precipitation. Though it was drier than normal, it was still much wetter than in recent months. Conditions were slightly wetter in Louisiana and Mississippi, though still drier than normal. Louisiana and Mississippi reported state average precipitation totals of 3.64 inches (92.46 mm) and 3.71 inches (94.23 mm), respectively.

Drought conditions in the Southern region did not change much in terms of extent; however, there were significant improvements in terms of intensity. In total, the region saw approximately a ten percent reduction in areal extent of each drought category. This equates to a one category improvement over much of the region. Exceptional drought, which last month covered over 40 percent of the region, was reduced to just under 30 percent. Drought conditions were removed in western Tennessee, and much of Arkansas was now drought-free. Some new moderate drought crept into southern Mississippi, but deterioration of drought conditions this month was fortunately minimal.

As summarized by the Midwest Regional Climate Center, November temperatures were above normal across the Midwest, but precipitation ranged widely. Parts of Minnesota and northwest Iowa received less than 0.10 inch (3 mm) and amounts increased to the south and east with the boot heel of Missouri and western Kentucky topping 10 inches (254 mm) for the month. Totals were near twice normal or more in swaths across northern Missouri to western Illinois and from the boot heel of Missouri up the Ohio River Valley and northward to western Lake Erie. Fall precipitation also ranged widely across the region. Three-month totals ranged from under 2 inches (51 mm) to nearly 20 inches (508 mm).

Drought conditions in the Midwest shifted to the west and north during November, continuing the migration seen in the fall season as a whole. November rains in Missouri, Illinois, and southeast Iowa led to improvements, or elimination, of drought conditions while dry conditions to the northwest led to degradations in Minnesota and northwest Iowa where Severe Drought designated areas expanded during the month.

Wet areas in the eastern half of the Midwest saw no relief as heavy rains fell in November. Harvest in Ohio was behind schedule due to wet soils and continued rains. Minor to moderate flooding was reported in Indiana, Ohio, and Kentucky late in the month. Cincinnati's airport station has already set an annual (calendar year) record precipitation total of 66.76" (1695 mm) with a month left in the year. The total is 27.72 inches (704 mm) above normal and already 9.18 inches (233 mm) above the old record from 1990. Records for the station extend back to 1869. Several nearby Kentucky stations are near their annual records as well.

As noted by the Northeast Regional Climate Center, November's temperatures averaged 44.0 degrees F (6.7 degrees C), making this the third warmest November in the Northeast since 1895. It was the eleventh consecutive month with above normal temperatures. Each of the states in the region had averages that were within the top 14 warmest in 117 years. Delaware and Maine ranked 2nd warmest, while New Hampshire, Rhode Island and Vermont saw their 3rd warmest November since 1895. It was the 4th warmest autumn (September - November) in the Northeast since 1895, with three states (Massachusetts, Rhode Island, and Vermont) having their warmest autumn in 117 years.

After three wetter-than-normal months, precipitation totals averaged on the dry side in November. The Northeast total of 3.20 inches (81.3 mm) was 84 percent of normal. New Jersey (106 percent), Pennsylvania (103 percent) and West Virginia (122 percent) were the only states with above normal totals. Departures in the drier-than-normal states ranged from 48 percent of normal in Maine to 99 percent of normal in Delaware. It was the 11th driest November in Maine since recordkeeping began in 1895. Autumn (September - November) precipitation totals averaged 14.69 inches (373 mm), which was 127 percent of normal. The Northeast saw its fifth wettest autumn in 117 years; with 18.25 inches (464 mm), Pennsylvania saw its wettest autumn on record. West Virginia's three-month total of 15.08 inches (383 mm) made this the 2nd wettest autumn since 1895 and Maryland's total of 16.96 inches (431 mm) ranked 3rd wettest on record. Six states (Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, and Vermont) and the region overall saw their wettest January through November in 117 years.

As explained by the High Plains Regional Climate Center, overall, the High Plains region experienced a warm and dry November. These conditions were favorable for crop producers and allowed most of the remaining harvesting activities across the region to be completed. The largest temperature departures were in the Dakotas, northern Nebraska, and pockets of eastern Colorado. In these areas, temperatures were generally 4-6 degrees F (2.2-3.3 degrees C) above normal. Below normal temperatures were confined to western Wyoming and a few isolated locations throughout the region.

November 2011 was drier than normal for most of the region. Many locations in North Dakota, South Dakota, and a swath running from southwest to northeast Nebraska received less than 25 percent of normal precipitation. According to the U.S. Drought Monitor, the ongoing lack of precipitation caused moderate drought conditions to spread into eastern North Dakota, eastern South Dakota, and northern Nebraska. Additionally, abnormally dry conditions spread across North Dakota and into parts of western South Dakota. For many locations, this autumn (September, October, and November) was one of the driest on record. One of the many locations to set records this autumn was Sioux Falls, South Dakota which only received 0.87 inch (22 mm) over the three month period. To put this amount into perspective, the normal precipitation for autumn in Sioux Falls is 6.30 inches (160 mm). The old record for driest autumn occurred in 1952 with 1.02 inch (26 mm) of precipitation (period of record 1893-2011). There were some exceptions to the dryness this month. Central Wyoming, southern and eastern Kansas, and the southeastern corner of Colorado all received at least 150 percent of normal precipitation. The precipitation was a welcome sight in the drought impacted areas of Kansas and Colorado. Heavy rains occurred November 7-8 in southern and eastern Kansas. During this time many daily precipitation records were set and, when combined with the rest of the month, the precipitation helped many locations to be ranked in the top 10 wettest Novembers on record. Topeka, Kansas received 2.98 inches (76 mm) over the two-day period, which included 2.05 inches (52 mm) on the 7th alone. This amount crushed a long-standing daily precipitation record of 1.43 inches (36 mm) set in 1918 (period of record 1887-2011). By the end of the month, Topeka had received 4.66 inches (118 mm) of precipitation which was the 8th wettest November on record. It is interesting to note that on average, November is usually one of the driest months of the year; however, this November was the second wettest month of 2011 in Topeka.

The USDM had many changes this month. Beneficial rains across southern and eastern Kansas led to one-category improvements for much of the drought stricken area. Additional improvements were made in south-central Colorado as two areas of extreme drought (D3) were downgraded to severe drought (D2). Only a small area of exceptional drought remained in southwest Kansas and the far southeast corner of Colorado. Nebraska and the Dakotas all had degradations, as precipitation totals were well below normal. Abnormally dry conditions (D0) spread across southern North Dakota and into northwestern South Dakota. Moderate drought (D1) spread south through eastern Nebraska and also developed in eastern North Dakota. According to the North Dakota State Climate Office, before the introduction of D1 this month, the state had gone 115 consecutive weeks with no drought. D2 spread into northeastern Nebraska and east-central South Dakota as well.

As summarized by the Western Regional Climate Center, several strong, deep troughs passed through the West this month, bringing cold Arctic air and slightly below to well below normal temperatures to areas west of the Rockies. The associated storm systems, however, generally resulted in precipitation values that were below normal. In part, the trajectories of these storms left many of them with insufficient moisture to produce typical November precipitation. Consequently, dry conditions dominated in the West this month. The Reno, Nevada airport tied its 7th driest November in a record beginning in 1937 with a precipitation total of 0.06 inch (1.52 mm). In central Oregon, the Redmond airport station also recorded its 7th driest year on record, with 0.21 inch (5.3 mm). Many eastern Oregon and Washington locations received only 50-75 percent of their normal precipitation amounts. Albuquerque, New Mexico had its 29th driest year on record, receiving 0.13 inch (3.3 mm).

Pockets of above-normal precipitation appear in the usually dry Southwest due to cutoff low systems that passed through the area this month. The much-needed precipitation from these systems helped to reduce the severity of the drought in western Arizona, though severe drought persisted in New Mexico. Wyoming also experienced pockets of above normal precipitation.

Upper Colorado River Basin: As reported by the Colorado Climate Center, the November 29th NIDIS (National Integrated Drought Information System) assessment for the Upper Colorado River Basin (UCRB) indicated that generous amounts of precipitation fell throughout the UCRB in November. Water-year-to-date (WYTD) SNOTEL precipitation percentiles were in the near- to above-average range throughout most of the UCRB, with the lowest percentiles (between the 30th and 50th percentiles) in the Gunnison River basin. As of November 27th, 88 percent of the USGS streamgages in the UCRB had normal (25th-75th percentile) or above normal 7-day average streamflows. About 14 percent of the gages in the basin had much above normal flows, while 11 percent were below normal. Most of the gages recording below normal flows were located in the southern part of the UCRB (in the San Juan basin). The VIC model continued to show dry soil moisture conditions in southeast Colorado. Dry soil conditions were showing up in Utah around the Colorado River valley and deteriorated in Sweetwater County, Wyoming. Wet soils were in the northern Colorado mountains and eastward. All of the major reservoirs above Lake Powell were near or above their November averages. Dillon, Green Mountain, Granby, and Lake Powell have all seen 2 percent or greater drops in levels this month. Flaming Gorge and Blue Mesa Reservoirs have only slight decreased, while Navajo has stayed at a nearly steady level for the month. Lake Powell was at 87 percent of average and 69 percent of capacity, compared to 61 percent of capacity one year ago.

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.

As noted by the National Weather Service office in Honolulu, persistent trade wind conditions during November helped bring near to above normal rainfall totals to many of the windward slopes of the main Hawaiian Islands. However, the persistent trades meant little rainfall occurred over leeward areas. On the Big Island, extreme drought, or D3 category conditions on the USDM map, in the south Kohala district and leeward north Kohala district spread into the Pohakuloa region of the Hamakua district. Extreme drought also continued over the southern portion of the Kau district. Severe drought, or D2 category conditions, remained over most of the north Kona district and over the mid-section of the Big Island from Pohakuloa to Kau. Wet windward conditions resulted in a retreat of moderate drought, or D1 category conditions, away from the lower elevations. On the island of Maui, early November rainfall provided some drought relief to the southeast slopes of Haleakala from Kepuni to Kaupo. However, extreme drought continued along the southwest Haleakala slopes from Kamaole to Ulupalakua. Elsewhere in Maui County, severe drought persisted over the lower elevations of west Maui from Maalaea through Lahaina and over the western third of Molokai. Heavy rainfall during the first half of November brought some drought relief to Kauai which went from severe drought to moderate drought over the Kalepa area near Lihue. The drought classification in east Oahu worsened to the severe category due to diminishing water levels in the Waimanalo reservoir. West Oahu stayed in the moderate drought category. Severe drought has affected portions of the state of Hawaii continuously since June 2008.

Some drought impacts in Hawaii include the following:

  • On Kauai, November rainfall helped improve pasture conditions in east Kauai.
  • On Oahu, the water level in the Waimanalo reservoir continued to decrease and has dropped over 40 feet since mid-May. The State of Hawaii Department of Agriculture implemented stricter conservation measures on November 18 and set a mandatory 20 percent cutback in irrigation water use.
  • On Molokai, the State of Hawaii Department of Agriculture has kept in place the mandatory 30 percent cutback in irrigation water consumption for the Kualapuu reservoir system.
  • On Lanai, no significant changes since the November 3 update. No additional impact information has been received.
  • On Maui, pastures and general vegetation remained dry over the leeward slopes of Haleakala especially from Kamaole to Ulupalakua. Water supply levels for upcountry Maui have improved since October due to an increase in windward Haleakala rainfall. However, the Maui County Department of Water Supply has maintained their call for a 5 percent reduction in water use. The request for a 10 percent reduction in water use by central and south Maui residents also remained in effect.
  • On the Big Island, pastures and general vegetation from Kawaihae to north Kona and from South Point to Pahala were in very poor condition and brush fires continued to be a significant concern. Many ranchers have already destocked cattle and water hauling operations have been ongoing for several months. A rancher recently reported having to sell replacement heifers which will result in a long-term impact. In September the USDA Farm Service Agency reported that various areas of the island had 30 to 100 percent loss of forage for livestock. Coupled with higher feed prices, the impact on ranching operations has been significant. In the south Kona district, yields for a wide range of fruit have decreased due to ongoing drought conditions.

SPI values for seven time periods for Hawaiian Island stations, computed by the Honolulu NWS office.
SPI values for seven time periods for Hawaiian Island stations

On other Pacific Islands, November was drier than normal in Guam and Kosrae and moderately dry at Saipan and Koror, but near to above normal at most other locations.

Pacific Island Percent of Normal* Precipitation
Station Name Dec 2010 Jan 2011 Feb 2011 Mar 2011 Apr 2011 May 2011 Jun 2011 Jul 2011 Aug 2011 Sep 2011 Oct 2011 Nov 2011 Dec 2010-Nov 2011
Chuuk 85% 76% 137% 156% 109% 66% 218% 124% 147% 120% 80% 135% 119%
Guam IAP 76% 205% 166% 138% 142% 95% 96% 195% 109% 121% 128% 75% 126%
Kapingamarangi 9% 22% 2% 61% 74% 69% 247% 199% 214% 181% 111% 76% 92%
Koror 75% 163% 145% 170% 130% 180% 129% 166% 145% 269% 107% 61% 144%
Kosrae 76% 82% 67% 51% 74% 151% 114% 76% 105% 86% 104% 82% 89%
Kwajalein 37% 119% 316% 277% 49% 91% 121% 100% 135% 101% 122% 137% 118%
Majuro 95% 100% 190% 188% 28% 109% 97% 118% 106% 108% 107% 125% 110%
Pago Pago 92% 183% 110% 52% 36% 35% 132% 40% 60% 26% 126% 143% 92%
Pohnpei 75% 98% 125% 148% 47% 95% 128% 85% 120% 97% 72% 124% 99%
Saipan 43% 182% 124% 164% 209% 154% 174% 110% 120% 64% 131% 51% 112%
Yap 69% 164% 123% 171% 129% 169% 113% 157% 133% 155% 101% 109% 132%
* 1971-2000 Normals

SPI values for seven time periods for Pacific Islands, computed by the Honolulu NWS office.
SPI values for seven time periods for Pacific Islands

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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 1966-2011 (46 years).

The Northern Hemisphere snow cover extent during November 2011 was much-above average, marking the 4th largest November snow cover extent on record and the third consecutive November with above-average snow cover extent. This is the largest November snow extent since 1993. During the month, the Northern Hemisphere snow cover extent was 36.4 million square km (14.1 million square miles), 2.8 million square km (1.1 million square miles) above the long-term average of 33.6 million square km (13.0 million square miles). The autumn season (September-November) snow cover extent was slightly above average, and ranked as the 15th largest (31st smallest) seasonal snow cover extent in the 46-year period of record.

During November, the North American snow cover extent was above average, ranking as the 13th largest (33rd smallest) November snow cover extent on record. This is the second consecutive November with above-average snow cover for North America, and the largest November snow cover extent since 2003. The monthly snow cover extent was 13.9 million square km (5.4 million square miles), 577,000 square km (222,780 square miles) larger than the long-term average. Several storms impacted the western half of North America, bringing above-average snow cover extent during November to the U.S. and Canadian Rockies and the Canadian prairies. Below-average snow cover was observed from the Canadian Maritimes into the Central U.S. Plains. For the autumn season, North America had near-average snow cover, ranking as the 21st largest (25th smallest) seasonal snow extent on record.

Eurasian snow cover was much-above average in November, and was the 5th largest November snow cover extent for the continent, at 2.2 million square km (849,000 square miles) above average. The November 2011 snow cover extent was the largest extent since 1993. Most of Europe had below-average snow cover extent during the month, as well as Southern China and the Himalayas. Eastern China, most of Mongolia, central China, and western Asia had much-above average snow cover during November. The autumn snow cover extent was also above average for Eurasia, ranking as the 15th largest (31st smallest) autumn snow extent on record.

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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 November 2011, was 10.01 million square km ( 3.86 million square miles). The monthly extent was 11.48 percent below the 1979-2000 average and ranked as the third smallest November Northern Hemisphere sea ice extent on record, behind 2006 and 2010. November 2011 is the 18th consecutive November and 126th consecutive month with below-average Arctic sea ice extent. Northern Hemisphere sea ice extent has decreased at an average rate of 4.7 percent per decade. The NSDIC reported that at the end of the month, the ice extent across the Chukchi, Barents, and Kara seas was below average. The Hudson Bay continued to be mostly ice free, which is typically ice covered at the end of November. Near-average ice coverage was observed in the East Greenland and Bering seas.

The November 2011 Southern Hemisphere sea ice extent was 0.53 percent below average — the 11th smallest (23rd largest) extent on record. This is the first November since 2002 with below-average Southern Hemisphere ice extent. This is in contrast to November 2010, when the ice extent reached its largest November value on record. Southern Hemisphere November sea ice has increased at an average rate of 0.6 percent per decade, with significant inter-annual variability.

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


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.

Troposphere

Lower Troposphere

November Lower Troposphere
November Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.12 +0.22 Coolest 23rd 1984 -0.52 -0.94 +0.16 +0.29
Warmest 11th 2009 +0.39 +0.70
RSS -0.06 -0.11 Coolest 13th 1984 -0.37 -0.67 +0.12 +0.22
Warmest 20th 2003 +0.25 +0.45
September-November Lower Troposphere
September–
November
Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.18 +0.32 Coolest 26th 1984 -0.48 -0.86 +0.17 +0.30
Warmest 8th 2010 +0.35 +0.63
RSS +0.04 +0.07 Coolest 19th 1984 -0.39 -0.70 +0.15 +0.26
Warmest 14th 1998 +0.28 +0.50
Year-to-Date Lower Troposphere
January–
November
Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.16 +0.29 Coolest 25th 1984 -0.34 -0.61 +0.14 +0.25
Warmest 9th 1998 +0.45 +0.81
RSS +0.05 +0.09 Coolest 22nd 1985 -0.37 -0.67 +0.14 +0.26
Warmest 12th 1998 +0.47 +0.85

Mid-troposphere

November Mid-troposphere
November Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.06 -0.11 Coolest 9th 1984 -0.27 -0.49 +0.04 +0.07
Warmest 25th 2009 +0.24 +0.43
RSS -0.10 -0.18 Coolest 9th 1985 -0.29 -0.52 +0.06 +0.11
Warmest 25th 2009, 2002 +0.24 +0.43
UW-UAH +0.04 +0.07 Coolest 16th 1984 -0.40 -0.72 +0.12 +0.22
Warmest 17th 2009 +0.32 +0.58
UW-RSS -0.02 -0.04 Coolest 15th 1985, 1984 -0.31 -0.56 +0.12 +0.22
Warmest 19th 2009 +0.30 +0.54
September-November Mid-troposphere
September–
November
Anomaly Rank
(out of 33 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.02 +0.04 Coolest 17th 1984 -0.33 -0.59 +0.08 +0.14
Warmest 16th 2010 +0.25 +0.45
RSS -0.02 -0.04 Coolest 14th 1985 -0.34 -0.61 +0.10 +0.18
Warmest 18th 1998 +0.26 +0.47
UW-UAH +0.12 +0.22 Coolest 24th 1984 -0.44 -0.79 +0.16 +0.28
Warmest 10th 2010, 1998 +0.35 +0.63
UW-RSS +0.07 +0.13 Coolest 19th 1984 -0.38 -0.68 +0.16 +0.28
Warmest 14th 1998 +0.34 +0.61
RATPAC* +0.12 +0.22 Coolest 43rd 1964 -0.86 -1.55 +0.16 +0.29
Warmest 12th 2006 +0.45 +0.81

*RATPAC rank is based on 54 years of data

Year-to-Date Mid-troposphere
January–
November
Anomaly Rank
(out of 33 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.01 +0.02 Coolest 17th 1984 -0.24 -0.43 +0.05 +0.10
Warmest 16th 1998 +0.45 +0.81
RSS 0.00 0.00 Coolest 17th 1985 -0.29 -0.52 +0.09 +0.16
Warmest 17th 1998 +0.46 +0.83
UW-UAH +0.09 +0.16 Coolest 24th 1984 -0.32 -0.58 +0.11 +0.21
Warmest 10th 1998 +0.55 +0.99
UW-RSS +0.07 +0.13 Coolest 23rd 1985, 1984 -0.32 -0.58 +0.14 +0.26
Warmest 11th 1998 +0.54 +0.97
RATPAC* +0.15 +0.27 Coolest 46th 1965 -0.79 -1.42 +0.15 +0.28
Warmest 9th 2010 +0.51 +0.92

*RATPAC rank is based on 54 years of data

Stratosphere

November Stratosphere
November Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.50 -0.90 Coolest 4th 2000 -0.70 -1.26 -0.46 -0.83
Warmest 30th 1982 +1.50 +2.70
RSS -0.43 -0.77 Coolest 4th 2000 -0.66 -1.19 -0.36 -0.65
Warmest 30th 1982 +1.36 +2.45
September-November Stratosphere
September–
November
Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.46 -0.83 Coolest 7th 2000 -0.65 -1.17 -0.44 -0.80
Warmest 27th 1991 +1.52 +2.74
RSS -0.39 -0.70 Coolest 6th 2000 -0.56 -1.01 -0.34 -0.60
Warmest 28th 1991 +1.47 +2.65
Year-to-Date Stratosphere
January–
November
Anomaly Rank
(out of 33 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.41 -0.74 Coolest 3rd 2008 -0.48 -0.86 -0.38 -0.68
Warmest 30th 1982 +1.01 +1.82
RSS -0.36 -0.65 Coolest 3rd 2008, 1996 -0.39 -0.70 -0.30 -0.54
Warmest 31st 1992 +0.97 +1.75

Background Information

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.

The mid-troposphere temperatures are centered in the in the atmospheric layer 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, creates 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.

References

Wildfires

Updated: 7 November 2011


Overview

During November 2011, approximately 270,518 acres (109,475 hectares) burned across the country, the third most on record for the month. The record for November acreage burned occurred in 2003, when 478,648 acres (193,700 hectares) were charred. During the January-November period, 8.5 million acres (3.4 million hectares) burned across the U.S. — the 3rd most in the 12-year period of record. The most acres burned during the January-November period occurred in 2006 when 9.51 million acres (3.8 million hectares) burned nationwide.

1-Month Wildfire Statistics*
November Totals Rank
(out of 12 years)
Record 2000-2010
Average
Value Year
Acres Burned 270,518 3ʳᵈ Most 478,648 2003 191,797
10ᵗʰ Least
Number of Fires 2,808 7ᵗʰ Most 10,223 2001 3,590
6ᵗʰ Least
Acres Burned per Fire 96.3 3ʳᵈ Most 227.5 2003 72.1
10ᵗʰ Least
3-Month Wildfire Statistics*
September–November Totals Rank
(out of 12 years)
Record 2000-2010
Average
Value Year
Acres Burned 1,543,659 3ʳᵈ Most 1,992,436 2007 1,038,936
10ᵗʰ Least
Number of Fires 12,759 7ᵗʰ Most 22,843 2001 14,667
6ᵗʰ Least
Acres Burned per Fire 121.0 3ʳᵈ Most 176.0 2006 78.6
10ᵗʰ Least
Year-to-Date Wildfire Statistics*
January–November Totals Rank
(out of 12 years)
Record 2000-2010
Average
Value Year
Acres Burned 8,499,701 3ʳᵈ Most 9,508,251 2006 6,434,326
10ᵗʰ Least
Number of Fires 66,629 8ᵗʰ Most 91,094 2000 73,841
5ᵗʰ Least
Acres Burned per Fire 127.6 2ⁿᵈ Most 139.0 2005 87.7
11ᵗʰ Least

*Data Source: The National Interagency Fire Center (NIFC)

Significant Events

One of the worst fires in Nevada history, according to media sources, broke out on November 18th near Reno. The Caughlin fire grew rapidly out of control with winds gusting to 60 miles per hour. The fire’s location near suburban Reno and its fast moving nature prompted the evacuation of 9,500 people. Dozens of homes and other structures were damaged or destroyed. A 74-year-old man died after he suffered a heart attack and lost control of his car while fleeing with his wife. The fire was particularly difficult to fight due to the combination of the high winds, rocky terrain, and accessibility. The fire was contained after burning nearly 2,000 acres.

Discussion

During November wetter than normal conditions were present across parts of the Southern Plains and South, stretching into the Great Lakes. Below normal precipitation was observed across Texas and Forida, New England, the Northern Plains and parts most of the West. Warmer-than-average conditions dominated east of the Rockies with the warmest temperature anomalies occurring across the Ohio Valley and Northeast. Below-normal temperatures were present for much of the West. See the U.S. Temperature and Precipitation discussion for more information. According to the U.S. Drought Monitor, during November, across the Contiguous U.S., the overall size of the drought footprint shrank. Drought conditions remained generally unchanged across the Southeast during the month. Drought conditions improved by one to two categories across Illinois, northern Missouri, and southern Iowa, while drought worsened in northern Iowa. The largest drought improvements were across the Southern Plains, where several storm systems brought beneficial rainfall to the drought-stricken region. Drought conditions improved anywhere from one to three categories across Oklahoma and Texas during the month, depending on where the precipitation fell. However, longer term precipitation deficits still exist across the region, and a large area of the Southern Plains are still experiencing extreme-to-exceptional drought. Drought conditions remained generally unchanged across the Southwest.

Wildfire information and environmental conditions are provided by the National Interagency Fire Center (NIFC) and the U.S. Forest Service (USFS) Wildland Fire Assessment System (WFAS).

At the beginning of November, there were two large wildfires active across the United States. One large wildfire was burning in western South Dakota, where dry conditions dominated during the last half of October. This created very dry small fuels (low 10-hour fuel moistures) and high fire danger across the region. The fire was mostly fueled by tall grasses and brush. A second large wildfire was burning across eastern Oklahoma. Long term dryness across the Southern Plains caused larger fuels (100-hour and 1,000-hour fuel moistures) to be very dry. Observed Keetch-Byram Drought Index (KBDI) values and fire danger were high across the region.

By the middle of November, two large wildfires were burning across the country — one in Virginia and one in the Florida panhandle. The fire in western Virginia was accompanied by low 100-hour fuel moistures, but all other measured variables were not conducive for wildfire development. Across the Florida panhandle, extremely high KBDI values and low 10-hour fuel moistures were reported.

At the end of November, two large wildfires were active in the United States. One large fire was burning in Illinois, where dryness in the short term caused low 10-hour fuel moistures. The second large wildfire was the Caughlin Fire near Reno, Nevada. Along the western extent of the Great Basin, low 10-hour fuel moistures and high KBDI values were reported at the end of November.


All Fire Related Maps


Citing This Report

NOAA National Climatic Data Center, State of the Climate for November 2011, published online December 2011, retrieved on September 18, 2014 from http://www.ncdc.noaa.gov/sotc/2011/11.