Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) temperature and precipitation outlooks for December and December-January-February (DJF), various short- and medium-range forecasts and models such as the 7-day quantitative precipitation forecast (QPF) totals from the Weather Prediction Center (WPC), the 6-10 day and 8-14 day CPC extended-range forecasts (ERFs), dynamical models at the monthly and seasonal time scale, climatology for DJF, and initial conditions such as soil moisture. The U.S. Drought Monitor valid on November 14, 2023 was used for initial drought conditions.

Following a dramatic reduction in drought coverage from over 90 percent at the start of the calendar year to just under 10 percent in early July, drought coverage slowly expanded to just over 20 percent of the Western Region during the fall. Much of this expansion occurred across the southern Four Corners region following a somewhat lackluster end to the monsoon season. Some drought expansion also occurred across the Northwest, where periods of late season heat exacerbated the climatologically dry conditions. DJF is a wet time of year for much of the West, and El Niņo events can bring enhanced Pacific moisture flow into California. Therefore, California, which is currently free of drought, is favored to remain free of drought through the DJF period. The CPC DJF outlook favors enhanced chances for above-normal precipitation across the Great Basin and western Arizona; therefore, drought reductions are possible in these regions. The signal becomes less clear across the remainder of the Four Corners region. Given the lack of a clear wet signal in the guidance along with a somewhat drier climatology, drought persistence is favored for eastern Arizona, New Mexico, and eastern Utah. Across the Northwest, warm North Pacific SSTs may provide opportunities for periods of enhanced moisture across the Northwest even if the favored storm track is shifted southward to California due to the ENSO response. Therefore, drought reductions are favored along and west of the Cascades. A warmer, drier signal is favored during El Niņo winters along the northern tier east of the Cascades; therefore, drought persistence is maintained in these regions.

Forecast confidence for the Western Region is moderate.

Robust precipitation episodes eroded ongoing drought conditions across the High Plains region during the past several months, particularly across portions of the Dakotas and Nebraska. Despite the reduction in overall coverage, drought conditions continue across much of Kansas, eastern Nebraska, southwestern Colorado, and portions of Wyoming and the Dakotas. Drought expanded and intensified across northeastern Kansas due to persistent dryness and abnormal warmth. The winter months are climatologically dry across the High Plains region, reducing the potential for substantial changes to the current drought depiction during the DJF period. The CPC December monthly outlook favors above-normal precipitation across much of the Great Plains, but due to the low climatological threshold, accumulations are not likely to be sufficient to effect large scale changes to the overall drought depiction. An active southern stream associated with El Niņo may bring some drought reduction to portions of Kansas, though confidence is fairly low due to the low climatology. To the north, the canonical El Niņo response favors above-normal temperatures and below-normal precipitation, making any further significant drought reductions unlikely. While some further drought development is possible across the northern High Plains, dry climatology coupled with typical freezing of soils and streams during the winter should limit the expansion of impacts through at least the end of February.

Forecast confidence for the High Plains region is low in the central Plains and moderate in the northern Plains.

Persistently dry, hot weather through the summer months led to a remarkable expansion of drought conditions across the lower Mississippi Valley and Tennessee Valley. Coverage of extreme (D3) and exceptional (D4) drought is currently highest in the Southern Region, with nearly half of the region experiencing at least severe drought, and almost three-quarters of Louisiana in exceptional drought. While widespread drought conditions continue across Texas and Oklahoma, recent conditions have been more favorable for amelioration. A wetter pattern has become established more recently, and over the next 7 days, the lower Mississippi Valley and Tennessee are forecast to receive 0.5 to 1.5 inches of rain. The CPC Days 8-14 precipitation outlook slightly favors a wet signal along the Gulf Coast. At the monthly and seasonal time scales, there is a strong connection between El Niņo and enhanced precipitation across the Southern Region due to a Pacific enhanced southern stream providing ample opportunities for winter storm formations. The CPC DJF precipitation outlook depicts unusually high probabilities (60-70 percent) for above-normal precipitation across southern Louisiana and Mississippi. These wet climate anomalies, coupled with a wet winter climatology and reduced evapotranspirative demand, strongly favor drought amelioration. Therefore, this forecast includes widespread drought removal, even for areas currently in severe drought. Improvement is indicated for portions of Louisiana and Mississippi in exceptional drought, as these impacts may be more difficult to fully eradicate by the end of February. The wet signal becomes less clear to the north and west of the highest elevations of the Appalachians; therefore, drought is favored to improve but not necessarily to be eliminated across northern Mississippi and Alabama, and drought persistence is favored for northern Tennessee. Drought reduction is favored for Oklahoma and the eastern half of Texas, but persistence is maintained for western Texas, where climatological precipitation is less and the El Niņo enhanced precipitation signal is weaker.

Forecast confidence for the Southern region is moderate.

Drought conditions generally eased across the Midwest region over the past month, particularly across the upper-Midwest and eastern Corn Belt. A drier regime became entrenched across the western and central Corn Belt over the past several weeks, however, and drought conditions have begun to gradually expand once again. DJF is a fairly dry time of year for the upper Mississippi Valley, though storm systems tracking along the Ohio Valley can bring more moisture opportunities to eastern portions of the Midwest region. Mostly dry weather is forecast during the upcoming 7-days, with the best chances for rainfall across southern Missouri and near the Ohio River. The dry pattern is favored to continue during Week-2 as well. Climate anomalies associated with El Niņo conditions favor increased chances for both below-normal precipitation and above-normal temperatures, and this is reflected in the CPC monthly and seasonal outlooks. Therefore, drought persistence is the most likely outcome in the Midwest. While continued drought development is possible, freezing soils and streams, especially across the upper-Midwest and Great Lakes regions where the dry signal is strongest, should help limit growing impacts from the dryness until the Spring thaw.

Forecast confidence for the Midwest region is moderate to high.

Drought conditions currently extend across more than half of the Southeast Region, which is fairly unusual for the Fall months. Persistent heat and dryness aggravated impacts, with severe to exceptional drought over portions of Alabama and Georgia, the uplands of South Carolina, and the Shenandoah Valley. Pockets of drought even extend across portions of Florida, despite the end of the climatological rainy season nearing. Wet weather is forecast to overspread much of the Southeast region over the next 7 days, and this wet pattern is favored to continue into Week-2. El Niņo winters tend to be much wetter than average across the Southeast, as an active southern stream provides ample opportunities for storm development. The CPC seasonal outlook favors above-normal precipitation across the Southeast region, with unusually high probabilities closer to the Gulf and South Atlantic coasts. Based on these forecasts, lower evapotranspirative demand during the winter months, and a generous precipitation climatology, widespread drought removal and improvement is forecast. While drought is favored to improve, it may not be completely removed from the higher elevations of northern Alabama and Georgia, and across the Shenandoah Valley and adjacent mid-Appalachians.

Forecast confidence for the Southeast region is high.

Less than 4 percent of the Northeast Region is currently experiencing drought conditions. Despite the overall favorable conditions, periods of dryness have persisted along the southern periphery of the region, and along the eastern shores of the Great Lakes. During the upcoming 7-days, widespread moderate to locally heavy rainfall is forecast to overspread the entire region, providing an opportunity for late-Fall soil moisture recharge. Drier and colder conditions are favored for Week-2, and with evapotranspiration demand much lower, impacts from dryness will be slower to materialize. El Niņo climate anomalies favor above-normal precipitation across the eastern seaboard from the mid-Atlantic through southern New England. This wetness should ameliorate remaining drought conditions across West Virginia and Maryland. In contrast, near- to below-normal precipitation is favored for western portions of the Northeast region, particularly near the Great Lakes. Therefore, drought persistence is favored for western New York and Pennsylvania, although drought expansion is unlikely this time of year.

Forecast confidence for the Northeast region is high.

No drought is currently depicted across Alaska. With the winter months favoring cold, dry, and dark conditions, there is little opportunity for any substantial drought development during DJF.

Forecast confidence for Alaska is high.

With enhanced convection shifted closer to the Equator due to above-normal SSTs across the East Pacific during El Niņo events and reduced trade winds, suppressed precipitation is forecast across Hawaii. Drought conditions have already expanded considerably across the islands over the past few months as El Niņo conditions developed and strengthened. With the wet season beginning in January, impacts from persistent dryness are likely to persist or even intensify. Therefore, persistence is forecast on this outlook, with development indicated anywhere where drought is not already entrenched.

Forecast confidence for Hawaii is high.

A small area of moderate drought (D1) remains across west-central Puerto Rico. The Caribbean basin typically experiences suppressed rainfall during El Niņo events. An active Central American Gyre may provide opportunities for tropical cyclone development over the next week, but most dynamical model forecasts keep these potential systems well west of Puerto Rico. Therefore, drought persistence is forecast, and no development is indicated in the absence of a stronger dry signal.

Forecast confidence for Puerto Rico is moderate.

Long term drought conditions persist across portions of the US Virgin Islands. Similar to Puerto Rico, given the potential for suppressed rainfall in association with El Niņo, drought persistence is the most likely outcome for the Virgin Islands. In the absence of a stronger dry signal, drought expansion is not currently indicated.

Forecast confidence for the US Virgin Islands is moderate.

Forecaster: Adam Allgood

Next Seasonal Drought Outlook issued: December 21, 2023 at 8:30 AM EST