Tools used in the U.S. Seasonal Drought Outlook (SDO) included the Climate Prediction Center (CPC) temperature and precipitation outlooks for July and July-August-September (JAS), 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 scales, climatology for the JAS season, and initial conditions such as soil moisture. The U.S. Drought Monitor valid on June 14 was used for initial drought conditions. La Nina conditions are present at the start of the JAS season, with enhanced chances that La Nina will persist through the end of September, according to the probabilistic ENSO outlook from CPC and the International Research Institute for Climate and Society. Thus La Nina composites for JAS were also considered.

Drought conditions remain entrenched across much of the Western Region, with just over 85 percent coverage as of the June 7th U.S Drought Monitor (USDM). Wet conditions during late Spring have resulted in substantial improvements across the Northwest and northern Rockies, with recent excessive precipitation resulting in flooding and substantial damage in Yellowstone National Park and other nearby regions. In contrast, hot and seasonably dry conditions have maintained or exacerbated drought conditions across the remainder of the West. In California, most major reservoirs are well below their historical levels at the start of the dry summer months, presenting significant supply concerns. JAS is a climatologically dry time of year for much of the Western Region, except across the Four Corners states, where some locations receive more than half of their annual precipitation from monsoonal convection. Dynamical models depict a fairly robust start to the Monsoon season across the Four Corners region, with locally heavy precipitation indicated on the WPC 7-day QPF, and enhanced precipitation favored on the 8-14 day ERF. The CPC June and JAS outlooks both favor an enhanced Monsoon season, with elevated chances for above-median precipitation across western New Mexico and Arizona in June, and primarily across Arizona in the JAS outlook. Periods of enhanced convection would likely yield some drought amelioration to parts of the Four Corners region, though improvements would be spotty and the overall long term drought situation would not likely be overturned. Elsewhere, equal chances for below-, near-, and above-median precipitation (EC) are favored across the West. Climatology yields no prospects for improvement across California, while recent moisture and forecasts for additional short term precipitation preclude any further degradations across the Northwest.

Forecast confidence is moderate for the Four Corners and northern Intermountain West, and high for the rest of the Western Region.

Over the past month, widespread heavy precipitation yielded substantial drought improvements across much of the High Plains Region, including central Kansas, southeastern Nebraska, and parts of the Dakotas. Despite this improved situation, large areas experiencing both short and long term drought conditions remain, with nearly 60 percent of the region depicted with drought coverage as of the June 7th USDM. While recent excessive heat has moved east of the region, scant precipitation is anticipated over the next 7 days. Some monsoonal moisture may generate convection across Colorado during late June, but below-average precipitation is favored on the JAS outlook from CPC for most of the region, except EC across the Dakotas. JAS is a fairly wet time of year for the Plains, with Gulf moisture fueling frequent thunderstorms and mesoscale convective systems (MCSes) that provide opportunities for localized drought improvement. Given the dry monthly and seasonal outlooks, however, widespread drought improvement is less likely than what may be observed in a typical summer. Therefore, drought persistence is the most likely outcome for the Plains, with increased chances for above-normal temperatures making some additional development possible across the more arid western parts of the region. Development is less likely across the northern tier and eastern High Plains, where moisture conditions are more favorable and the forecast below-average precipitation signal at the seasonal time scale is less pronounced.

Forecast confidence is moderate to high for the High Plains Region.

Widespread heavy rainfall over the past few weeks brought substantial reductions to drought intensity across North Texas and western Oklahoma, and drought amelioration to central Oklahoma and parts of far southern Texas. In contrast, hot, drier conditions exacerbated existing drought and resulted in an expansion of abnormal dryness (D0 USDM depiction) across central and eastern Texas and much of Louisiana. Recent heat and dryness have also resulted in a reduction of soil moisture across the lower Mississippi Valley, especially northern Mississippi and western Tennessee, with pockets of D0 impacts beginning to appear. Forecasts through the end of June depict little relief for the areas that missed out on the recent rainfall, with hot conditions and below-average rainfall favored across much of the Southern Region. Given the incipient deteriorating conditions, eastern Texas and the lower Mississippi Valley are primed for flash drought development through the end of June, with further degradations possible into July across the lower Mississippi Valley given the CPC June outlook favoring below-median rainfall. There is high uncertainty whether this rapid onset drought situation would result in impacts that last through the end of the JAS season, particularly given that September is the peak of the Atlantic hurricane season. Climatological rainfall is highest along the immediate Gulf Coast, where the seasonal outlook maintains EC; therefore, some drought improvement is possible across southern Louisiana through the end of the period. Given the forecasts favoring above-average temperatures for both June and JAS, the prospects for improvement of early summer flash drought conditions are lessened across eastern Texas and the lower Mississippi Valley. Therefore, development is indicated on the outlook. Above-average temperatures may also result in drought redevelopment across parts of west-central and northern Texas that were recently ameliorated. No drought development is currently depicted across eastern Oklahoma and most of Arkansas, where recent heavy rainfall boosted soil moisture levels.

Forecast confidence is moderate for the Southern Region.

The Midwestern Region is mostly drought free as of the June 7th USDM, with only a small area of D1 (moderate drought) impacts across western Iowa. While short and medium range forecasts depict a fairly dry and hot end to June across the region, heavy rainfall over the past few weeks, including frequent MCS activity, boosted soil moisture across eastern Indiana and Ohio, making drought development unlikely. Incipient conditions are worse, however, across the central Corn Belt, including southeastern Missouri, western Kentucky, much of Illinois, western Indiana, and portions of Iowa. Similar to the lower Mississippi Valley, these areas are primed for early summer flash drought development. Should these drought conditions materialize over the next several weeks, the CPC monthly and seasonal outlooks both favor above-average temperatures throughout the Midwest, and below-average rainfall during June, continuing across western areas through JAS. Therefore, despite a fairly generous precipitation climatology, the prospects for early season drought conditions to improve substantially by the end of September are reduced. As a result, drought development is favored across parts of the central Corn Belt, as well as western Iowa where soil moisture remains low. This forecast features increased uncertainty, as the probabilities for above-average temperatures are fairly low, and periods of organized convection or even recurving tropical cyclones later in the period could result in rapid improvements.

Forecast confidence is low to moderate for the Midwest Region.

Despite a fairly cool Spring, increasing evapotranspiration rates coupled with long-term below average precipitation has resulted in drought development for parts of coastal New England. Further south, areas of drought remain entrenched across portions of southern Georgia and along the southern Atlantic coast, despite some spotty convection bringing limited relief. An early season tropical disturbance that later developed into Tropical Storm Alex brought copious rainfall to South Florida, which, coupled with the onset of the summer seabreeze-convergence convective regime, has eliminated all remaining drought across the state. During the remainder of June, periods of extreme heat are forecast across the Southeast, which, coupled with only light convection, may result in a rapid onset of drought conditions across portions of northern Florida and along the Piedmont of Georgia and the Carolinas. Note that while this early summer development is favored, it is not depicted on this seasonal drought outlook, as we currently do not favor the impacts to last through the end of September. Both the June and JAS CPC precipitation outlooks favor above-average rainfall, and the peak of an anticipated active hurricane season in September may provide additional opportunities for moisture surges. Therefore, while new drought impacts are likely during the early part of the outlook period, these impacts are not favored to last through the end of September. Across New England, meager rainfall forecast through the end of June does not favor drought reduction in the short term, but near to below-normal temperatures should preclude rapid deterioration. Despite a warm outlook for June through September, both the June and JAS outlooks favor enhanced precipitation, making drought improvements the most likely outcome.

Forecast confidence is moderate for the Southern and Northeastern Regions.

Meager spring runoff coupled with above-average temperatures has resulted in widespread abnormal dryness across southwestern Alaska, with some areas of moderate drought developing on the latest USDM. Above-average temperatures favored at all time scales within the JAS period may make this newly developed drought more intractable, despite a fairly wet climatology and precipitation forecasts maintaining EC. Further north across central Alaska, both the June and JAS CPC outlooks slightly favor above-average precipitation, thus drought improvements are more likely across the northernmost drought area. In the absence of a clear dry signal, no further drought expansion is favored. Dynamical model forecasts and La Nina climatology strongly favor suppressed rainfall across Hawaii; therefore continued expansion of drought conditions into areas already abnormally dry is likely. Drought conditions have also expanded recently across Puerto Rico, but the La Nina response typically results in enhanced precipitation across the Caribbean region. The summer months are a wet time of year for Puerto Rico, with frequent convection and potential tropical cyclone activity. Therefore, drought improvement appears to be the most likely outcome.

Forecast confidence is moderate for Alaska, high for Hawaii, and moderate for Puerto Rico.

Forecaster: Adam Allgood

Next Seasonal Drought Outlook issued: July 21, 2022 at 8:30 AM EDT