Drought - October 2010
Contents Of This Report:
National Drought Overview
Detailed Drought Discussion
October 2010 was drier (39th driest) and warmer (11th warmest) than normal when weather conditions are averaged across the country. But considerable variability occurred throughout the month (weeks 1, 2, 3, 4, 5) and on a regional basis. Beneficial precipitation improved drought conditions in the Far West, Mid-Atlantic to Northeast, and parts of Hawaii. The month was drier than normal across much of the Southeast to southern Plains and central Plains to Midwest, with drought and abnormally dry conditions expanding across parts of the Gulf Coast and Central Plains states and from the Lower Mississippi to Ohio valleys. Soil moisture and pasture and rangeland continued to deteriorate in parts of the South to Ohio Valley.
The weather pattern for October over the Lower 48 States generally consisted of a battle between the Bermuda High pressure system and cyclonic storms moving through the mid-latitude jet stream flow. The Bermuda High (also known as the North Atlantic High) brought warmer-than-normal temperatures to much of the country and blocked tropical systems from reaching the mainland U.S. for most of the month. Upper-level ridging in the jet stream helped amplify the warm temperature anomalies over the West, contributing to the fourth warmest October in Wyoming and seventh warmest October in Montana. With tropical systems mostly penned up in the Gulf of Mexico and Caribbean or deflected into the Atlantic, and the moisture source for cold fronts effectively blocked, much of the southern Plains, Southeast, and Midwest had drier-than-normal weather, with drought intensifying over Florida and from the Ohio to Lower Mississippi Valleys. Florida had the driest October on record, Missouri fourth driest, Texas eighth driest, and Indiana eleventh driest.
Several strong low pressure systems and moist fronts affected parts of the country during the month. The remnants of Tropical Storm Nicole brought beneficial rain to the Northeast at the beginning of the month, effectively busting the drought along parts of the Atlantic seaboard. A series of strong cyclonic storms dumped rain and snow over much of the West, bringing much-needed drought relief. A particularly intense low pressure system moved across the central U.S. near the end of the month. This brought record low barometric pressure readings, hurricane-force winds, intense rainfall, hail and tornadoes to a large portion of the country from the Canadian border to the Gulf of Mexico, as well as blizzard conditions to the northern Plains. The cold front associated with the low brought beneficial rain to parts of the drought-stricken Southeast. When all was said and done, October 2010 ranked as the wettest October on record for Nevada, second wettest for Vermont, fourth wettest for New York, fifth wettest for New Hampshire, and seventh wettest for California.
By the end of the month, the core drought areas in the U.S. included:
- much of Hawaii, where moderate (D1) to exceptional (D4) drought was entrenched;
- the southern Plains to Southeast and Ohio Valley, where moderate (D1) to extreme (D3) drought expanded; and
- the central Appalachians and Klamath Valley of Oregon-California, where moderate to severe drought lingered, and the Arrowhead of Minnesota, central High Plains, and parts of the West, where moderate drought lingered.
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. As seen on the Palmer Z Index map, low precipitation resulted in very dry conditions for October 2010 over much of the Gulf Coast and parts of the Southeast. Low precipitation, coupled with enhanced evaporation from above-normal temperatures, created dry conditions across much of the Ohio Valley and parts of the central Plains and northern High Plains to northern and central Rockies. Wet conditions are evident on the Z Index map across the Northeast, parts of the northern Plains and Upper Mississippi Valley, and large parts of the West where major cyclonic weather systems brought abundant rain and/or snow. Compared with the September 2010 PHDI map, the October 2010 PHDI map indicates that drought conditions worsened over Florida and the Lower Mississippi to Ohio valleys but improved over the Northeast and much of the West. It also shows that wet conditions were entrenched over the northern Plains to Upper Mississippi Valley, but Texas was drying out. The October 2010 PHDI map also reflects the long-term nature of the drought conditions. The Z Index and PHDI maps in combination show that the dryness in the Southeast to Ohio Valley is both a short-term and long-term phenomenon, that the dryness in the Plains and much of Texas is a short-term phenomenon, and that long-term dry conditions are still evident in parts of the mid-Atlantic to Northeast in spite of recent wetness.
Standardized Precipitation Index
The Standardized Precipitation Index (SPI) measures moisture supply. The six SPI maps here show the spatial extent of anomalously wet and dry areas at time scales ranging from one month to 24 months. Dryness is evident at 1 to 12 months from east Texas to the Lower Mississippi Valley and up the mid-Mississippi into Ohio valleys. Central and southern Texas are dry at the 1-month time scale but neutral or wet at the other time scales. Parts of the Southeast show deficits from 1 month to 9 months, except Florida which is mostly dry for most of the time scales, even out to 24 months. Dryness is especially acute from the Ohio to Lower Mississippi valleys for the last 1 to 3 months. Parts of the northern High Plains, northern to central Rockies, and central Plains to Midwest show deficits for October and, to a lesser degree, the last 2 to 6 months. Wet conditions are indicated for the Far West at 1 to 3 months and the northern Plains at 2 to 3 months spreading further east and south from 6 to 24 months. Also wet are parts of the Northeast at all time scales and the mid-Atlantic coast from 2 to 3 months and 12 to 24 months. Parts of the Southwest are wet at 9 to 12 months and the Southeast at 24 months.
Abnormal dryness and drought were evident in several indicators. There were hardly any days with rain in Florida and Texas and from the northern and central Plains to the Ohio Valley. This resulted in long runs of consecutive dry days in some of these areas. On the other hand, parts of California and the Great Basin had long runs of dry days in between heavy rain events which bracketed the month (weeks 1, 2, 3, 4, 5). Soil moisture conditions improved during October along the East Coast and parts of the South (October 31 versus September 26). But in areas where beneficial rains did not fall, warmer-than-normal temperatures resulted in above-normal evaporation which contributed to further drying of thirsty soils. Soil moisture, as observed (percent of topsoil dry and very dry and comparison to median) and monitored by several models (NOAA Climate Prediction Center anomalies and percentiles, Leaky Bucket, NLDAS [North American Land Data Assimilation System] top soil layer and total soil layer, VIC [University of Washington Variable Infiltration Capacity macroscale hydrologic model]), was still drier than average across much of the country from the Gulf Coast to Ohio Valley, from the southern to central Plains, and parts of Hawaii and Alaska. Soils were especially dry from the Ohio to Lower Mississippi valleys, and in Florida. According to October 31st U.S. Department of Agriculture (USDA) reports, over 70 percent of the topsoil was rated short or very short (dry or very dry) in Kentucky (88 percent); Louisiana (80 percent); Arkansas and Colorado (78 percent each); Alabama (73 percent); and Florida (72 percent); with over 90 percent rated short or very short in Indiana (93 percent).
For much of the country, cooler autumn weather brings agricultural activity to an end during October. Dry weather can help or hinder the harvesting and planting of crops, depending on soil moisture conditions and antecedent rainfall. According to the November 2nd Weekly Weather and Crop Bulletin (WWCB), 91 percent of the nation's corn crop was harvested — the earliest date that harvest surpassed the 90 percent mark; 96 percent of the soybean crop was harvested; and 92 percent of the winter wheat crop had been seeded. Although field work was ahead of schedule for many crops, pasture and rangeland conditions deteriorated from the Gulf Coast to the Great Lakes. By October 31, the USDA reported that more than two-thirds of the pasture and rangeland were in poor or very poor condition in Kentucky (89 percent), Indiana (82 percent), Alabama (73 percent), Mississippi (69 percent), and Tennessee (66 percent). Satellite monitoring of vegetation health (Vegetation Drought Response Index [VegDRI], Vegetation Health Index [VHI]), and the U.S. Geological Survey (USGS) agro-hydrologic model (Soil Water Index [SWI], Water Requirement Satisfaction Index [WRSI]), indicated stress on vegetation across the Southeast to Ohio and Lower Mississippi valleys, and in parts of the High Plains.
More well monitoring stations (real-time network, climate response network, total active network) in the drought-stressed areas showed low groundwater this month compared to a month ago. Streamflow (observed and modeled [CPC anomalies and percentiles, VIC 1-, 2-, 3-, 6-month]) was below average for the month from the Gulf Coast to Ohio Valley and parts of Alaska and Hawaii.
Did You Know?
The precipitation pattern in Alaska for October 2010 was mixed, with drier-than-normal conditions dominating at the southern and interior stations, while temperatures were above normal across the state. Consequently, snow water content of the early winter snowpack was drier than normal. Below-normal precipitation was widespread for the last 2 to 3 months, so little change occurred in the USDM drought depiction. Long-term dry conditions persisted in many locations at the year-to-date and 6-, 12-, 24-, and 36-month time scales. Below-normal streamflow was observed in the southern portions of the state and modeled soil moisture deficits existed across most of the state, although soil moisture conditions become less relevant this time of year as the ground freezes.
Below-normal precipitation fell along the northeastern portion of Puerto Rico during October, reflecting a pattern stretching back the last 60 to 90 days. But the dry areas become near normal or wet at the 180 day and year-to-date time scales. Streamflow for Puerto Rico was above normal and the island remained drought free on the November 2nd USDM map.
A few stations in Hawaii had above-normal rainfall during October, but most reported below-normal amounts. Long-term deficits (year-to-date and last 3, 6, 12, 24, 36 months) continued to climb. The current drought is the most severe and extensive in the 10-year USDM record. At mid-month, there were reports of 90 percent pasture losses and herd culling exceeding 30 percent in areas of southwestern Maui. But enough beneficial rain fell to improve drought conditions in favored windward locations on the southern islands by the end of the month. The percent area of the state classified in moderate (D1) to exceptional (D4) drought contracted from about 74 percent at the end of September to about 51 percent by the end of October. As noted in the November 2nd USDM, streamflows and reservoirs have been responding favorably in the windward areas, but the lee sides of the islands remained in moderate to extreme drought; thus mitigation measures and mandatory water restrictions remained in place as a precaution.
On a statewide basis, October 2010 was drier than normal for many states in the Southeast, Midwest, and southern to central Plains. Florida had their driest October and September-October in the 116-year record. Missouri had their fourth driest October, Texas their eighth driest, and Indiana eleventh driest. The same areas were drier than normal for the last three months (August-October). States with much below normal precipitation included Florida (third driest), Indiana (fourth driest), Wyoming (tenth driest), and Louisiana (twelfth driest). Wet weather dominated the northern Plains and Upper Midwest for the last six months (May-October), with Minnesota and Wisconsin each having their wettest May-October on record. But the Southeast continued dry at this 6-month time scale, with Florida having the second driest May-October on record. In fact, Florida had the second driest June-October and July-October as well, and the fourth driest April-October. The dryness in the Southeast was accompanied by near-record heat during May-October. Dryness dominated the year-to-date (January-October) in the Southeast and Ohio Valley, with Louisiana ranking as fifth driest.
Percent area of the Western U.S. in moderate to extreme drought, January 1900-October 2010, based on the Palmer Drought Index.
October 2010 was wetter than normal across much of the Far West and Great Basin, but drier than normal for parts of the Rockies. This month marked the beginning of the new water year, defined as October through the following September. Based on the high elevation (SNOTEL network) stations, the precipitation pattern for the current water year (October 2010) was wetter than average in most river basins. The snow water content of the mountain snowpack was mixed for October 2010, but this is early in the snow season. An analysis of early data by the USDA indicated that reservoir levels were generally mixed. The decade-long drought in the West has had a severe impact on the level of Lake Mead. By the end of October 2010, data from the U.S. Department of the Interior Bureau of Reclamation indicated that the level of Lake Mead had dropped to 1082.36 feet, which is the lowest level since the lake was filled in the 1930s. The previous lowest level was 1083.57 feet, reached in March 1956 during the peak of the 1950s drought. According to media reports, the lake is now just 8 feet above the level that would trigger the first drought restrictions, which would reduce water supplies for Arizona and Nevada (azcentral.com, 10/19; Circle of Blue Water News, 9/22). According to the USDM, 5 percent of the West was experiencing moderate to severe drought at the end of October, down 3 percent compared to September, while the Palmer Drought Index statistic dropped to about 3 percent.
A more detailed drought discussion, provided by the NOAA Regional Climate Centers and others, can be found below.
As noted by the Southeast Regional Climate Center, October was an extremely dry month across nearly the entire Southeast, owing to a lack of tropical storms and persistent ridging across the southern U.S. The lack of rainfall was particularly noteworthy across Florida, where 19 locations experienced their driest October on record, 16 of which recorded no measurable precipitation for the month. This included the Jacksonville area, which experienced its first precipitation-free October and third precipitation-free month ever in a record extending back to 1871. Orlando International Airport recorded a streak of 33 consecutive days without measurable precipitation, the fourth longest precipitation-free streak ever in a record extending back to 1954. Strong storms in advance of a cold front connected with an intense Midwest cyclone brought some much needed rain to parts of the Southeast towards the end of the month. These storms dumped between 3 and 5 inches (76.2 and 127 mm) across sections of southern Alabama, northern Georgia, and western North Carolina. Parts of the region were also affected by two tropical cyclones in the month of October. Hurricane Otto dumped over 12 inches (304.8 mm) of rain across Puerto Rico and the U.S Virgin Islands between the 5th and 7th of the month, resulting in severe flooding on the islands. For the month, the Charlotte Amalie Airport on the U.S. Virgin Islands recorded 16.2 inches (411.5 mm) of rain, making it the wettest October on record and coming within 0.3 inches (7.6 mm) of setting a new all-time monthly record. Hurricane Paula brought heavy rains to parts of the Florida Keys on the 13th and 14th of the month. Nearly 4 inches (101.6 mm) of rain fell at Curry Hammock State Park, while less than 2 inches (50.8 mm) fell at Key West International Airport. Traces of snowfall were observed on some of the higher peaks of the southern Appalachian Mountains (Beech Mountain, North Carolina and Mount Mitchell, North Carolina) on the 6th of the month in association with a deep upper-level low centered over the mid-Atlantic region.
Average temperatures for October were generally above normal across the Southeast region. The greatest departures occurred through portions of central North Carolina and Virginia [3-4 °F (1.6-2.2 °C) above normal] while South Carolina, Georgia, and Alabama were 1-2 °F (0.5-1.1 °C) above normal. In contrast, temperatures were near normal to slightly below normal across much of Florida and Puerto Rico. The predominantly dry weather regime that prevailed across the Southeast in October resulted in strong radiational cooling and some chilly nights across a broad stretch of the region. In contrast, warm southwesterly flow became established over the Southeast region from the 25th to the 28th of the month in response to an intense low pressure system centered over the upper Midwest and a deep ridge over the Atlantic Ocean. This resulted in unusually high daytime and overnight temperatures across the Southeast. Remarkably, over this four-day period, a total of 520 daily high minimum temperature records were either tied or broken. Another 412 daily maximum temperature records were also tied or broken during this period.
The overall dry pattern in October resulted in an expansion of drought conditions (D1 and greater) throughout the Southeast, particularly in the southern tier of the region. The most notable change in the USDM was the expansion of severe (D2) and extreme (D3) drought through Alabama, the Florida Panhandle, and the east coast of Florida from Jacksonville to West Palm Beach. The impacts of the dry weather on agriculture across the Southeast were mixed. The harvesting of row crops, such as peanut and soybean, was made especially difficult in October due to the hardened soils. However, the continued warm, dry weather allowed grape harvests in parts of Virginia to thrive, and wineries in the region projected a successful 2010 vintage.
NOAA's Winter Outlook, released by the Climate Prediction Center on October 21, indicated a continuation of above average temperatures and below average rainfall across the Southeast through February. This projection is largely in response to a strengthening La Niña pattern over the equatorial Pacific Ocean, which is expected to persist into the spring. This could mean an intensification and expansion of drought conditions across the Southeast over the next several months, which would place additional stress on water resources and agriculture, as well as increase the risk of wildfires.
As explained by the Southern Regional Climate Center, October average daily temperatures varied throughout the Southern Region; however, for the most part, values remained near normal. For the majority of the Southern region, October was a very dry month. In fact, the region-wide averaged precipitation total was only 1.25 inches (31.75 mm), making it the eleventh driest October on record (1895-2010). The state of Texas averaged only 0.8 inches (20.32 mm) of precipitation for the month, which makes it the eighth driest October on record (1895-2010). Both Arkansas and Louisiana experienced their thirteenth driest October on record (1895-2010), with state average precipitation values of 1.23 inches (31.24 mm) and 1.25 inches (31.75 mm), respectively. Only a small area of the region experienced above normal precipitation for the month. This included eastern Tennessee, northwestern Texas, and eastern Oklahoma. Precipitation totals there varied from 130-200 percent of normal. In the case of northwestern Texas and eastern Oklahoma, most of the monthly precipitation was delivered from one rainfall event that occurred on the 22nd of the month. For example, Slaton, Texas received 3.66 inches (92.96 mm) for the month, of which 3.61 (91.69 mm) fell on the 22nd alone. Elsewhere, most stations reported values that ranged from 5 to 50 percent of normal. The driest areas included much of southern Texas where most stations reported less than a tenth of an inch (2.54 mm) for the month. This area was extremely dry, with over 50 stations failing to record any precipitation at all. None of the stations in Texas climate division 10 reported precipitation. Conditions were also extremely dry in northeastern Arkansas. Most of the stations in that division reported less than an inch (25.40 mm) of rain. In Louisiana and southern Mississippi, a majority of stations reported precipitation values that fell 2-3 inches (50.80 - 76.20 mm) below the monthly normal.
Drought conditions deteriorated during October over vast areas of the Southern region. As of September 28, 2010, 20 percent of the region had moderate drought conditions or worse, 6.8 percent had severe drought conditions or worse and only 0.8 percent had extreme drought conditions. As of November 2, 2010, 37 percent had moderate drought conditions or worse. The expansion from 20 percent of the region includeed parts of southern Texas, eastern Texas and southern Tennessee. In addition, the areal coverage of severe drought tripled over the Southern region. The areal coverage of severe drought conditions or worse made up 18.6 percent of the region (as of November 2, 2010). Severe drought expanded in areas including southern and eastern Arkansas, northern and western Louisiana, western Mississippi, and western Tennessee. Moreover, there was also an expansion of extreme drought from 0.8 percent in September to 4.2 percent in October (based on the November 2, 2010 USDM). Areas experiencing severe drought included central and northeastern Louisiana, southeastern Arkansas, southwestern Mississippi, northeastern Arkansas, and northwestern Tennessee.
In Texas, the October dryness and an anticipated lack of precipitation during the 2010-2011 cool season have fueled fears that the upcoming wildfire season could be one of the worst in years. Burn bans were in place across most of Southeast Texas and much of East Texas as soil moisture levels have dropped to critically low levels. The region of most concern for the upcoming cool season was North Texas, where rainfall during the first nine months of 2010 has been abundant. This has allowed for growth of vegetation that is expected to dry out and act as fuel for wildfires during the upcoming period of forecasted dryness. The combination of plentiful rainfall and warmer temperatures during the second half of summer was a good recipe for cotton, which was expecting a near-record yield. However, there was concern that hail and heavy rains caused damage to a number of South Plains cotton fields. The same combination of above normal precipitation earlier in the year and recent dryness was expected to produce a bumper pecan crop in West Texas. This fall's deer season was expected to be great because of an abundance of forage and overall good health of the Texas deer population. (Information provided by the Texas State Climate Office)
As summarized by the Midwest Regional Climate Center, October was drier than normal for most of the Midwest. Northeast Ohio was slightly above normal as was northwest Wisconsin. In northern Minnesota there were pockets that received 50 percent more precipitation than normal. The rest of the region was below normal and in many places well below normal. Iowa, Missouri, Indiana, southern Illinois, and western Kentucky got less than half their normal rainfall in October. Statewide Missouri had the 4th driest October in 138 years and the driest since 1964. Most of the region received little to no rain for the first three weeks of the month. October was warmer than normal for the region. Maximum temperatures were even more above normal while minimum temperatures were closer to normal. The enhanced daily temperature range was consistent with the dry weather and high pressure in place for most of the month. Harvest progressed rapidly and earlier than normal. Crops matured early and the weather in late September and most of October provided ideal conditions for fieldwork. Given the chance to bring in the crops early, the farmers took advantage wrapping harvest up at one of the earliest times on record.
As noted by the Western Regional Climate Center, precipitation was well above normal for most of the Great Basin, southern California, southern Utah and northern Arizona. The Pacific Northwest was above normal while much of the Rockies were below normal. Reno, Nevada, recorded their wettest October on record (1937+), and in fact has received about 35 percent of their annual water year precipitation in the first month of the new water year. Winnemucca, Nevada, recorded their 2nd wettest October in 100 years. San Diego, California, measured their 4th wettest October in 96 years while Santa Barbara, California, their 3rd wettest in 70 years. Oddly enough, the 3 wettest Octobers on record in Santa Barbara have all occurred in the past 7 years. The wet October conditions resulted from a series of upper-level weather systems. The major events included an early October cutoff low that stalled over the Great Basin, a cutoff low that formed over southern Nevada at mid-month, and a powerful storm along the Pacific coast October 23-24 that hit northern California and the Sierra Nevada with strong winds of over 130 mph along the mountain crests and heavy rain.
Temperatures were above normal throughout the West except for portions of California and Oregon. Parts of Montana and Wyoming had a very warm month. In Cut Bank, Montana, and Sheridan, Wyoming, it was the warmest October since 1965 and in Great Falls, Montana, it was the warmest since 1974. Generally speaking, the warmth of this month was influenced more by the above-average nightly minimum temperatures. Consequently the region saw far fewer days below freezing than in typical Octobers. Daytime temperatures were cool in California and Nevada.
As explained by the High Plains Regional Climate Center, October 2010 was warmer than normal across the High Plains region and drier than normal for most areas. Several locations in Wyoming ranked in the top 10 warmest Octobers on record. Large portions of eastern Colorado, central Kansas, and eastern Nebraska along with smaller areas of southwestern North Dakota, western South Dakota, and western Wyoming received less than 25 percent of normal precipitation. The ongoing lack of precipitation caused abnormally dry and moderate drought conditions to expand in eastern Colorado, southwestern Wyoming, and the panhandle of Nebraska. The exceptions were west-central Colorado, eastern Wyoming, and south-central South Dakota where total precipitation for the month was 150 percent of normal or greater. In west-central Colorado, many locations ranked in the top 10 wettest Octobers on record. An intense low pressure system brought rain, snow, and strong winds to parts of the region October 26-27. In South Dakota, the precipitation from this storm was enough to push Sioux Falls up to the wettest year on record (period of record 1893-2010).
Changes to the USDM by the end of October included the following. Below normal precipitation and declining soil moisture levels led to the expansion of abnormally dry conditions (D0) in western Kansas. A new area of D0 developed in central Nebraska as well. The moderate drought conditions (D1) in central Colorado and extreme southern Wyoming that developed last month spread further east in Colorado, and into the southeast corner of Wyoming and the panhandle of Nebraska. Only small areas of D1, in north-central and southwestern South Dakota, north-central Colorado, and extreme western Wyoming, were eliminated.
The warm weather and dryness for most of the month allowed producers to make significant harvest progress. According to the USDA National Agricultural Statistics Service, many row crop harvests across the region were ahead of the 5-year average by the end of the month.
As summarized by the Northeast Regional Climate Center, the Northeast had above normal precipitation totals in October. The regional total was 5.52 inches (140 mm), which was 159 percent of normal. It was the Northeast's wettest October since 2006. Two states had below normal rainfall totals: Rhode Island (72 percent) and West Virginia (81 percent). Rainfall departures among the rest of the states ranged from 121 percent of normal in Connecticut to 236 percent of normal in Vermont. It was the Northeast's 11th wettest October since recordkeeping began in 1895. Four states were also in the top 11 wettest since 1895: Vermont, 2nd; New York, 4th; New Hampshire, 5th; and Maine, 11th.
Wet weather during October eased drought conditions throughout the region. As of October 26, 2010, the USDM maps indicated the following for the Northeast. Much of eastern West Virginia, including the eastern panhandle, was in moderate or severe drought, while central portions were abnormally dry. The adjoining western panhandle of Maryland was also experiencing moderate to severe drought conditions. South central Pennsylvania was under moderate drought conditions; most of the western half of the state was abnormally dry. Small areas of New Jersey, Connecticut and Massachusetts were also abnormally dry.
October was the tenth month in a row with above normal temperatures in the Northeast. All of the states in the region averaged either exactly normal or above. Most locations in the region saw the end to the growing season by the end of October. Eastern Maryland, Delaware, coastal New York and parts of New Jersey, however, were still waiting for their first fall frost by month's end.
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.):
|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.|
|Contiguous United States|
- Palmer Drought Indices
- Standardized Precipitation Index
- long-term (36 to 60 month) percent of normal precipitation maps
- airport station percent of normal precipitation maps
- statewide precipitation rank maps
- Cooperative station percent of normal precipitation maps
- percent of average maps for the SNOTEL stations in the western mountains provided by the Western Regional Climate Center
- satellite-based observations of vegetative health
- National Weather Service model calculations of soil moisture, runoff, and evaporation
- National Weather Service model calculations of soil moisture using the Leaky Bucket Model
- Midwest Regional Climate Center model calculations of soil moisture
- topsoil moisture conditions observed by the USDA and mapped by the Climate Prediction Center
- pasture and range land conditions observed by the USDA and mapped by the Climate Prediction Center
- streamflow maps maintained by the USGS
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