Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) temperature and precipitation outlooks for May and May-June-July (MJJ), various short- and medium-range forecasts and models such as the 6-10 day and 8-14 day CPC extended-range forecasts (ERFs), dynamical models at the weekly, monthly, and seasonal time scale, climatology for MJJ, and initial conditions such as soil moisture. The U.S. Drought Monitor valid on April 16, 2024 was used for initial drought conditions.



There has been a steady decline in drought coverage across the nation for the past several months. On October 24, 2023, more than one-third of the country was experiencing drought. Less than one-half year later (24 weeks) on April 9, 2024, less than 15 percent of the country was covered. Shortly after the start of the 2022-23 wet season, on November 1, 2022, over 73 percent of the West Region was experiencing drought. Move forward 17.5 months (not quite two full wet seasons) and in early April 2024, only about 21 percent of the West Region is in drought, and California is entirely free of drought. The trend toward drought reduction is expected to end for the time being, however, as declining precipitation climatology in most of the region and seasonally-increasing temperatures make substantial, widespread improvement unlikely through the end of July. In most areas west of the Cascades and Sierra Nevada, May-July typically brings only 2 to 10 percent of the annual precipitation. The climatology gets wetter farther east, with the 3-month period averaging 15 to 30 percent of the annual total from the Cascades and Sierra Nevada eastward to the northern Rockies and the southern High Plains. May-July is part of the wet season on the eastern fringes of the West Region, with easternmost Montana typically receiving 45 to 60 percent of their annual precipitation during this 3-month period, similar to areas farther east in the Great Plains. In the Southwest, precipitation usually picks up markedly in later June and July as the seasonal monsoon circulation gets underway. In the higher elevations of southern Arizona and New Mexico, precipitation generally ranges from almost 0 to about 3.5 percent of the annual total in May, to between 1 and 5 percent in June, to between 17 and 20 percent in July. Areas of drought from the central Rockies westward will very likely persist and perhaps deteriorate through the end of July due to the dry climatology. Across the northern part of the region from central Montana westward, the May-July Outlook favors below-normal precipitation, and in areas with the most enhanced chances for subnormal precipitation and relatively dry antecedent conditions, drought expansion is forecast. Drought persistence with some expansion is also expected in parts of the Southwest and southern High Plains not already entrenched in drought, as most dynamical models as well as the official May-July Outlook anticipate a slow start to the monsoon season. There are enhanced chances for subnormal May-July precipitation in some areas of the central Four Corners region with antecedent long-term dryness, but drought is not expected to develop there due to considerably above-normal winter snowpack. Forecasts for drought improvement or removal are limited to parts of eastern Montana and adjacent Wyoming where May-July climatology is markedly wet and soil moisture increases more often than it drops during the period.



Forecast confidence is moderate for most of the Western Region, but high along the western tier.



As spring got underway two years ago (mid-March 2022), over 80 percent of the High Plains Region was entrenched in drought. A bit more than a year later (late April 2023), about half of the Region was still in drought. But on April 9, 2024, drought coverage in the High Plains Region dropped to 15.7 percent, the lowest since 14.7 percent on May 5, 2020. This is a very wet time of the year in most of the Region, with 40 to 60 percent of the annual precipitation total typically falling during May-July east of the Rockies, and modeled soil moisture increases from mid-April to the end of July at least 75 percent of the time regionwide. The May Outlook shows slightly enhanced chances for above-normal precipitation across most of Kansas, Nebraska, and South Dakota, with no tilt of the odds toward dryness or wetness elsewhere. The May-July Outlook depicts equal chances of below, near, or above-normal precipitation. Based on climatology and the May outlook, drought removal or improvement is forecast in most areas of drought. The exception is the areas typically affected by the monsoon in southern parts of the Region. With the expected weak start to the monsoon and some antecedent dryness in place, drought persistence and development is anticipated across a sizable portion of Colorado.



Forecast confidence is moderate for the High Plains Region.



Drought covered almost 74 percent of the Southern Region in late October 2023, but primarily due to heavy rains in the Lower Mississippi Valley, 5 months later in late March, less than 15 percent of the Region was in drought. Coverage has increased slightly to 16.3 percent on April 9, primarily due to some development from northern Oklahoma eastward into northwestern Tennessee. Drought is currently affecting much of southern and western Texas, part of the northern tier of the Region from the northeastern Texas Panhandle to northeastern Arkansas and adjacent Tennessee, and a small patch in southwestern Oklahoma. The western tiers of Texas and Oklahoma are affected by the southwestern monsoon later in the period, and receive 40 to 50 percent of their annual precipitation during May-July. Farther east, the period leans a little wetter than other times of year along the central Gulf Coast and in the South-Central Plains, but is neither wet nor dry compared to the rest of the year elsewhere. In western parts of the Region, the monsoon should be the primary source of precipitation, and most indicators, along with the official May-July Outlook, call for a weak start to the monsoon with subnormal precipitation. In contrast, from the Lower Mississippi Valley and adjacent areas eastward, the May and May-July Outlooks show enhanced odds for above-normal precipitation. In between these two areas, neither unusually wet nor dry longer-term conditions are favored, but some dynamic models show the potential for heavy precipitation during the last half of April and slightly beyond. Given all these considerations, the forecast calls for drought persistence or intensification in the western tier of the region, with some expansion into more of western Texas. Given the wetter signals farther east, existing areas of drought should experience improvement or removal..



Forecast confidence is moderate for the Southern Region.



Across the Midwest region, Much of the area west of the Mississippi River is entrenched in drought, including most of the state of Iowa. Drought becomes less widespread farther east, affecting only parts of southern and west-central Illinois, southern and northern Wisconsin, and northern Michigan. Drought coverage in the Region was 26.6 percent on April 9, down from over 42 percent just four weeks prior. May-July is a markedly wet time of year in Minnesota and northern Iowa, with 40 to 45 percent of the annual precipitation typically observed. The wetness of the season relative to other times of year decreases to the south and east, and for the eastern Great Lakes and areas closer to the Ohio River, May-July is not markedly wet or dry compared to other times of the year. As a result, climatologically, soil moisture increases more than 75 percent of the time during this forecast period in northwestern parts of the region, but it dries out more than 75 percent of the time in the eastern Great Lakes and close to the Ohio River. The 3-month forecast for May-July favors above-normal precipitation for the Middle Mississippi and Ohio River Valleys, and shows equal chances across the north half of the Region. The forecast is based on the 3-month outlook and climatology, calling for drought improvement or removal from the Middle and Lower Mississippi Valley eastward through the western half of the Great Lakes Region, but expecting drought persistence across northern Michigan where May-July climatology is a little drier and dynamical models show slightly lower precipitation totals over the next few weeks.



Forecast confidence is moderate for the Midwest Region.



The Southeast Region is free of drought, and the May-July Outlook favors above-normal precipitation for almost the entire region, with equal chances forecast for the lower Florida Peninsula. Therefore, drought is not expected to develop by the end of July .



Forecast confidence is high for the Southeast Region.



Drought has been removed from the Northeast Region. The 3-month Outlook for May-July shows enhanced odds for wetter than normal weather across the southern half of the Region, with no tilt of the odds farther north. Looking at precipitation seasonality, May-July is slightly wetter than most other times of the year along the northwestern tier of the region, and typically tilts neither wet nor dry elsewhere. Given the forecasts, current conditions, and climatology, there is no reason to expect drought development anywhere by the end of July, but with less confidence than areas farther south.



Forecast confidence is moderate for the Northeast Region.



No drought is currently in place across Alaska, but some abnormal dryness has been noted in far southeastern parts of the state, primarily due to an unusual lack of cold-season snowfall. No drought development is anticipated at this time, but there is a slightly enhanced risk in the southeastern part of the state and this region will need to be monitored.



Forecast confidence is high for most of Alaska, but moderate in the Southeast.



Across Hawaii, there has been a little drought improvement recently, but this appears to be temporary. Drought remains in most leeward areas over the southern half of the state, and with subnormal rainfall favored for May-July, drought should persist or worsen slightly. Some expansion into other leeward areas of the island chain is possible, but there is not enough confidence to identify any specific area as having a significantly elevated chance.



Forecast confidence is moderate for Hawaii.



With a wetter pattern for the past few weeks, drought conditions have receded slightly across Puerto Rico in the past few weeks. The wet pattern and trend toward drought reduction is favored to continue, but only slightly, reducing confidence in the forecast of drought removal by the end of July..



Forecast confidence is low for Puerto Rico.



Drought conditions were recently removed from the U.S. Virgin Islands, which have been affected by the same wet pattern as observed across Puerto Rico. The wet pattern is only slightly favored to continue, but it seems unlikely that conditions will dry out sufficiently to allow drought to develop by the end of July.



Forecast confidence is moderate for the US Virgin Islands.



Forecaster: Rich Tinker



Next Seasonal Drought Outlook issued: May 16, 2024 at 8:30 AM EDT