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Drought and Climate for December 2020: Drought increases in southern and western US, improves in Northeast

by Curtis Riganti

Drought


Over the course of December, drought expanded to the south and west, ultimately covering a large portion of central and southern California in moderate drought or worse conditions. The drought situation improved markedly in the Northeast during December. Parts of coastal New England that started the month in extreme drought had improved all the way to abnormal dryness by the end of the year, while large swaths of moderate drought in Pennsylvania and New York also were eradicated. Nationally, moderate drought coverage increased from 40.17 to 40.97 percent, severe drought coverage increased from 26.67 to 28.60 percent, extreme drought coverage increased from 17.57 to 18.56 percent, and exceptional drought coverage slightly increased from 8.24 to 8.26 percent.  

Drought Outlook


The Climate Prediction Center is forecasting much of the western drought to persist, with a few areas of improvement. Oregon, northern California, and central Washington are forecast to see improvement in drought conditions during January, as is south-central Idaho. Southeast Nebraska and adjacent northeast Kansas, eastern Texas, south-central Oklahoma, and other spotty areas of drought in the South and Midwest are forecast to improve. Drought removal is also forecast in the remaining areas of long-term drought in the Northeast.

Temperatures


Overall, the United States experienced a warmer than normal December, with much of the central and northern Lower 48, Alaska, and Hawaii having above-normal temperatures. Two of the warmest areas were in the northern Great Plains and northern New England, where temperatures from 6 to 12 degrees above normal were commonplace. Arizona and Utah, as well as western portions of Colorado and New Mexico, experienced colder than normal temperatures. For more regionally specific information, please refer to the regional paragraphs below.

Precipitation


Precipitation was highly variable across the United States during December. The Northeast and Mid-Atlantic were primarily wetter than normal. California and adjacent portions of Arizona and New Mexico were mostly drier than normal for the month. Elsewhere, a mix of drier and wetter conditions occurred. Please see the regional paragraphs below for more details.

Access the latest monthly drought outlook from NOAA's Climate Prediction Center.

The two maps above are from the High Plains Regional Climate Center.

Find these and other products related to the U.S. Drought Monitor on the USDM website.

Regional Overviews


Northeast

During December, the majority of the Northeast received near-normal or above-normal precipitation. Compared to normal, one of the wettest areas was in north-central Pennsylvania and south-central New York, where a major snowstorm occurred near the midpoint of the month. Southern New England was also much wetter than normal during December. Widespread swaths of the Northeast received at least 150 percent of normal precipitation for the month. Warmer-than-normal temperatures were common in northern New England, where temperatures of at least 5 degrees above normal were widespread. Temperatures moderated toward 2 to 4 degrees above normal or near normal farther south in the region. Drought coverage was drastically reduced during December, falling from 21.09 to 3.63 percent.

Southeast

The Southeast remained drought-free during December. Scattered locations in Alabama, Georgia, and South Carolina, and much of the east-central Florida coast, received below-normal precipitation. Florida and southern Georgia were generally 2 to 5 degrees cooler than normal, while South Carolina was generally 1 to 4 degrees below normal. Elsewhere, temperatures were variable.

South

Temperatures during December were generally near or slightly below normal in Tennessee, Mississippi, and Louisiana, while temperatures from 2 to 6 degrees warmer than normal were common in northwest Arkansas, Oklahoma, and parts of Texas. Above-normal precipitation was common in southeast Texas, northwest Louisiana, and northwest Oklahoma, while much of the western Texas Panhandle was quite dry. Moderate drought coverage slightly increased from 45.58 to 45.97 percent, severe drought coverage increased from 23.04 to 26.45 percent, extreme drought coverage increased from 12.55 to 15.39 percent, and exceptional drought coverage remained at 6.58 percent.

Midwest

During December, below-normal precipitation occurred in a large area extending from central and southern Missouri to Kentucky, central and southern Illinois, Indiana, and western Ohio. Northern Iowa, southern Minnesota, northern Wisconsin, and northern Michigan also were drier than normal for December. Most of the region had warmer than normal temperatures. Compared to normal, the warmest areas were in Minnesota and northern Wisconsin, where temperature departures from 4 to 10 degrees above normal were common. Farther south and east, temperatures from 2 to 6 degrees above normal were widespread. Moderate drought expanded in northwest Minnesota during December, and regional moderate drought coverage increased from 9.05 to 12.36 percent. Severe drought coverage slightly increased from 2.22 to 2.26 percent, while extreme drought coverage remained at 0.45 percent. 

High Plains

Precipitation departures from normal varied widely across the region. Generally, central and western North Dakota were drier than normal, while parts of south-central Kansas and central Nebraska were wetter than normal. To the east of the Continental Divide, above-normal temperatures covered nearly the entire region. The warmest areas were in North Dakota and northern Wyoming, where temperatures from 6-12 degrees above normal were common. Drought covered much of the region in December, including all of Colorado and most of Nebraska. Regional moderate drought coverage increased from 80.71 to 82.46 percent, severe drought coverage increased from 49.79 to 50.36 percent, extreme drought coverage rose from 26.78 to 27.09 percent, and exceptional drought coverage rose slightly from 5.53 to 5.71 percent.

West

A dry pattern continued across large portions of the West in December as drought continued in many areas. Much of California was drier than normal during December, and drought expanded through much of the central and southern part of the state. Parts of southern Nevada, Arizona, and northern Utah were also quite dry compared to normal for December. Northwest Washington, and parts of northwest Oregon, in contrast, were wetter than normal. Temperatures across the northern and western tier of the region were warmer than normal, in particular in Montana, where temperatures of at least 6 degrees above normal were widespread. Cooler than normal temperatures generally prevailed west of the Continental Divide in Colorado and New Mexico, eastern Arizona, and Utah. Moderate drought coverage increased from 75.55 to 78.63 percent, and severe drought coverage increased from 60.85 to 65.18 percent.  Extreme drought coverage increased from 44.67 to 46.49 percent, and exceptional drought coverage increased slightly from 22.10 to 22.16 percent.

Alaska, Hawaii and Puerto Rico

Warmer than normal temperatures occurred across Hawaii in December, with most temperatures ending up between 1 and 4 degrees above normal for the month. Most areas were also quite dry, as many locations received less than 25 percent of their normal rainfall. However, a few areas saw improvement in conditions, and overall drought coverage decreased. Moderate drought coverage dropped from 22.62 to 19.31 percent, severe drought coverage lessened from 12.98 to 9.68 percent, and extreme drought coverage decreased from 3.41 to 2.60 percent. Alaska remained free of drought in December. Below-normal precipitation fell in east-central Alaska, while southeast Alaska was wetter than normal for December. The majority of the state was warmer than normal, with temperatures of 2 to 8 degrees above normal commonplace. Temperatures were within a degree or two of normal across Puerto Rico. South-central and parts of southwest Puerto Rico received above-normal precipitation during December, while much of northern Puerto Rico was drier than normal for the month. A couple of areas of moderate drought developed in north-central Puerto Rico, bringing the percent coverage from zero to 3.31.

Movers and Shakers for December 2020
StatePercent Area
Dec. 1, 2020
Percent Area
Dec. 29, 2020
StatusChange
Biggest increase in drought
Arizona92.8293.86Extreme1.04
California75.0395.17Moderate20.14
California48.1974.34Severe26.15
California19.3633.75Extreme14.39
Colorado93.7193.73Severe0.02
Colorado74.6876.17Extreme1.49
Colorado26.7127.60Exceptional0.89
Idaho19.3220.67Moderate1.35
Idaho4.204.24Severe0.04
Illinois9.8716.36Moderate6.49
Illinois1.682.02Severe0.34
Minnesota10.7023.40Moderate12.70
Missouri7.1010.22Moderate3.12
Montana31.8534.41Moderate2.56
Montana7.848.27Severe0.43
Nebraska93.4499.13Moderate5.69
Nebraska48.8150.99Severe2.18
Nevada99.3699.71Moderate0.35
Nevada83.2191.18Severe7.97
Nevada69.9072.49Extreme2.59
Nevada21.2323.68Exceptional2.45
North Dakota76.5683.68Moderate7.12
North Dakota54.7359.44Severe4.71
Oklahoma25.1825.21Moderate0.03
South Dakota58.6758.83Moderate0.16
South Dakota10.6110.65Severe0.04
Tennessee5.327.16Moderate1.84
Texas79.4081.10Moderate1.70
Texas43.5650.33Severe6.77
Texas24.4730.09Extreme5.62
Utah95.0797.38Severe2.31
Washington8.888.93Severe0.05
Biggest decrease in drought
Arizona98.3598.34Severe0.01
Arizona76.8172.69Exceptional4.12
Arkansas10.716.87Moderate3.84
Hawaii22.6219.31Moderate3.31
Hawaii12.989.68Severe3.30
Hawaii3.412.60Extreme0.81
Kansas60.5559.79Moderate0.76
Kansas20.4719.69Severe0.78
New Hampshire57.4812.20Moderate45.28
New Mexico100.0099.97Moderate0.03
New Mexico53.2753.20Exceptional0.07
New York26.045.98Moderate20.06
Oklahoma7.797.75Severe0.04
Oregon84.1083.53Moderate0.57
Oregon69.0868.71Severe0.37
Oregon34.7027.74Extreme6.96
Vermont48.0734.74Moderate13.33
Wyoming55.7754.22Severe1.55

December 2020 impact summary: Drought restrictions implemented in Texas; drought plan activated in Colorado

by Denise Gutzmer

The NDMC added 54 impacts to the Drought Impact Reporter during December as drought intensified in California and other areas of the U.S. and eased in the Northeast and southern Great Plains.  Texas had 23 impacts, documenting numerous fire and water restrictions.  Colorado and Oregon trailed with 5 impacts apiece as drought responses were undertaken. 

 

Texas drought restrictions; winter wheat, pastures needed rain

Although some parts of Texas received abundant rainfall in December, other parts of the state, such as Far West Texas, the Panhandle and South Texas, were very dry, leading to restrictions on outdoor burning, fireworks and water use.  In western Texas, the backcountry area around Guadalupe Peak in Guadalupe Mountains National Park was closed from Dec. 20 through Jan. 4, due to continued drought, per National Parks Traveler.  Resource damage and illegal fire violations were occurring at backcountry sites, prompting park authorities to close the area to backcountry camping. 

Toward the latter part of December, water restrictions were newly introduced in Burnet County and Corpus Christi, as reported in DailyTrib.com and Corpus Christi Business News, as groundwater levels fell and lakes and reservoirs became depleted. 

In many parts of the Lone Star State, rain was needed for the emergence of winter wheat as some areas did not have adequate soil moisture for germination, according to AgriLife Today.  Many livestock were receiving supplemental feed as pastures were dry and also in need of moisture.

 

Colorado’s Drought Plan fully activated

Persistent, intense drought in Colorado led Gov. Jared Polis to shift from Phase 2 to Phase 3 of its State Drought Mitigation and Response Plan, according to the Colorado Water Conservation Board.   The Municipal Water Impact Task Force will convene and coordinate with water providers to prepare for potential water challenges in 2021.

The agricultural portion of the plan was activated during the summer, requiring government agencies serving farmers and ranchers to start coordinating aid efforts, as noted in The Colorado Sun.  Officials from several cities feared that the drought was severe enough to warrant hasty preparations for short water supplies in 2021. 

While the Upper Colorado River Basin was at 70 percent of its normal snow water equivalent in mid-December, other locations in western Colorado were not faring as well, as reported by Summit Daily.  The warm, dry autumn made it difficult for ski areas to open additional terrain with artificial or natural snow.

 

New Mexico water shortages

Persistent drought led New Mexico authorities to prepare for the continuation of drought into 2021.  New Mexico state and local officials met virtually to discuss the ongoing drought and water shortages occurring and expected to continue into the next year, per Carlsbad Current Argus.  Two poor monsoon seasons and a dry start to winter have left much of the state in exceptional drought with low water supplies.

In southeast New Mexico, the Carlsbad Irrigation District was unable to get its full allotment from Brantley Lake, leading the Interstate Stream Commission to continue to use augmentation pumps to make up the shortfall for the district. 

 

Low initial water allocation in California

California experienced a dry fall and early winter, leading to the intensification of drought in November and December.  Rainfall amounts across much of California since Oct. 1, the start of the water year, were mostly less than 50 percent of normal.  With low precipitation, the California Department of Water Resources announced the initial water allocation of 10 percent for the State Water Project.  While the initial allocation was low, the allocation last year was also 10 percent, but was increased to 20 percent in May 2020. 

 

Maine Drought Task Force ended

Precipitation eased drought in Maine in recent months after an intense summer of drought.  The Maine Drought Task Force met on Dec. 17 to review conditions, per Penobscot Bay Pilot.  With drought easing across the state, the Task Force opted to close and reconvene in the spring of 2021 if conditions warrant.

Low hay availability in Maine after a summer of poor hay production led farmers to seek new strategies to protect hay condition.  Various agricultural insurance policies and strategies for securing reliable hay were discussed during a virtual talk hosted by the University of Maine’s Department of Agriculture. 

 

For more details, please visit the Drought Impact Reporter.

The images above summarize information from the Drought Impact Reporter.