Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) temperature and precipitation outlooks for August and August-September-October (ASO), 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 ASO, and initial conditions such as soil moisture. The U.S. Drought Monitor valid on July 16, 2024 was used for initial drought conditions.



The combination of little to no precipitation, above-normal temperatures, and periods of enhanced winds have increased the chance of drought development in the next month across the northern High Plains, northern Rockies, Intermountain West, and parts of the Pacific Northwest and northern California. The development is generally designated where abnormal dryness exists in the U.S. Drought Monitor valid July 16th. Once this drought develops, it is likely to persist into the early fall. Elsewhere throughout the northern half of the West, the lack of a wet signal at any time scale and likelihood of excessive heat at times through August support persistence of ongoing drought. For the Four Corners Region and Southwest, forecast confidence is lower since near to above-normal precipitation is favored during late July. Persistence or development remains favored for Arizona and southwestern Utah, but only persistence is forecast for ongoing drought areas of New Mexico. Since 30-day precipitation has averaged above-normal and only slightly elevated below-normal probabilities are forecast in the ASO outlook, forecast confidence is too low to designate any widespread development to New Mexico.



Forecast confidence ranges from high (northern half of the West) to low (Southwest).



The eastern Dakotas are excessively wet, while abnormal dryness and moderate to severe drought exist across the Central High Plains and Front Range of the Colorado Rockies. Due to increasing precipitation deficits along with excessive heat and high evapotranspiration rates the next two weeks, the rapid onset of drought is underway and is likely to expand across the Central High Plains. Since the ASO outlook favors below-normal precipitation and above-normal temperatures, additional development and persistence of ongoing drought is forecast across Wyoming, northeastern Colorado, southwestern North Dakota, and western parts of South Dakota, Nebraska, and Kansas.



Forecast confidence is moderate for the High Plains Region.



The rapid onset and intensification of drought also affected much of Tennessee and northern Mississippi. Since the next two weeks are forecast to be relatively wet and there is no dry signal in the seasonal forecast tools, removal or improvement is forecast for this short-term drought. The Lower Mississippi Valley and eastern Texas are expected to remain drought-free given antecedent wetness, a relatively wet pattern during late July, and either equal chances (EC) of below, near, or above-normal precipitation or elevated above-normal precipitation probabilities in the ASO outlook. Farther to the west across the Southern Great Plains and Middle to Upper Rio Grande Valley, there are varying levels of drought intensity. Based on the ASO temperature and precipitation outlooks, persistence is forecast. Based on short-term indicators such as 30-day precipitation and soil moisture along with late July forecasts and consistent with the ASO outlook, development is forecast across parts of southwestern Oklahoma and northwestern Texas.



Forecast confidence is moderate for the South Region.



During June and early July, a lack of adequate precipitation along with above-normal temperatures and high evapotranspiration rates led to pockets of drought development across parts of the eastern Corn Belt and Ohio Valley. Since the 8-14 day outlook leans wet and the ASO outlook calls for equal chances (EC) of below, near, or above-normal precipitation, removal of this short-term drought is forecast. Forecast confidence is low though given the lack of any strong wet signal and expected periods of heat through at least the late summer. Elsewhere, across the Great Lakes and Middle to Upper Mississippi Valley, excessive wetness is present after frequent heavy precipitation during the spring and early summer. Given this antecedent wetness, no drought development is forecast.



Forecast confidence ranges from low (Ohio Valley) to high (Upper Mississippi Valley) for the Midwest Region.



Similar to the Northeast region, a rapid onset and intensification of drought occurred across Virginia, the Carolinas, Georgia, and northern Alabama. Removal or improvement is forecast due to: 1-3 inches of rainfall during the next week, the 8-14 day outlook favoring above-normal precipitation, and the ASO outlook leaning wet. Forecast confidence for drought amelioration or its end are highest across the Coastal Plain of the Southeast where heavier rainfall is expected during the next two weeks and climatology is slightly wetter. Another factor that could eventually bring improvement during the outlook period is the potential for heavy rainfall associated with a tropical cyclone. Closer to the foothills and along the Central to Southern Appalachians, recovery is expected to be slower with drought impacts lingering. Following drought emergence across the Florida Peninsula this past spring, the start of the convective season resulted in improvement. Any lingering drought over the Florida Peninsula is likely to end during the next several weeks.



Forecast confidence ranges from moderate (Coastal Plain) to low (foothills and Central to Southern Appalachians) for the Southeast Region.



Drought rapidly developed and intensified throughout the Mid-Atlantic and Central Appalachians during June and early July. As of mid-July, soil moisture is lowest (below the 5th percentile) across eastern West Virginia with 28-day average streamflows well below average for West Virginia, southern Pennsylvania, and parts of Maryland to New Jersey. After a heat wave ends on July 17, model guidance indicates a moderation in temperatures and an increasing chance of beneficial precipitation during the remainder of July. Based on this pattern change and the seasonal precipitation outlook favoring above-normal precipitation, drought removal or improvement (D2+ in the USDM) is forecast for the Mid-Atlantic and Central Appalachians. Another factor that could eventually bring improvement during the outlook period is the potential for heavy rainfall associated with a tropical cyclone. Forecast confidence is lowest across the severe (D2) to extreme (D3) drought areas of eastern West Virginia, western Virginia, and western Maryland where impacts may linger and a slow recovery is expected.



Forecast confidence is moderate to low for the Northeast Region.



Alaska is mostly drought-free with only a small moderate drought area designated for southeastern Alaska. Since above-normal precipitation is favored at all time scales within the outlook period, removal is forecast.



Forecast confidence is high for Alaska.



Persistence is forecast for ongoing drought areas of Hawaii based on the North American Multi-Model Ensemble. Development is most likely for the Big Island of Hawaii and also for the leeward side of Kauai.



Forecast confidence is moderate for Hawaii.



Puerto Rico has remained drought-free since late April. Given the antecedent wetness, wet climatology, and the North American Multi-Model Ensemble favoring above-normal precipitation, development is unlikely through the end of October.



Forecast confidence is high for Puerto Rico.



Similar to neighboring Puerto Rico and for the same reasons, the U.S. Virgin Islands are likely to remain drought-free through the end of October.



Forecast confidence is high for the U.S. Virgin Islands.



Forecaster: Brad Pugh



Next Seasonal Drought Outlook issued: August 15, 2024 at 8:30 AM EDT