Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) temperature and precipitation outlooks for October and October-November-December (OND), 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 OND, and initial conditions such as soil moisture. The U.S. Drought Monitor valid on September 19, 2023 was used for initial drought conditions.

Autumn is a month of transition in the West Region, and there are a variety of climatological changes that occur during later autumn and early winter (October - December). The monsoon in the Southwest northward into the Four Corners States is usually on the wane before the end of September, and October-December is typically much drier there. Farther north, in east Montana, climatological precipitation slowly decreases during autumn, and October - December is the drier season for the region. In contrast, October are relatively dry months in the Pacific Northwest, but the wet season typically begins to ramp up quickly during November.

During the past four weeks, widespread drought degradation and expansion was observed over the Pacific Northwest, Northern Rockies and southern parts of the Four Corners region due to episodes of extreme heat and dryness across the regions. In contrast, 1 to 2 class drought improvement occurred over parts of southeastern California and adjacent Nevada and Utah due to exceptionally heavy precipitation brought by Hurricane Hilary and its remnants to much of this climatologically arid region. For the coming October-December, across areas of drought in the West - 1 class improvement is forecast along the coastal areas of the Pacific Northwest due to an increasingly wet climatology and a favorable time of year for soil moisture, while persistence is likely over existing drought regions across eastern parts of the Pacific Northwest and Northern Rockies with likely development over anomalous dry interior areas in central Washington and parts of central Idaho and western Montana. Persistence is expected for parts of the Four Corners region due to weak wet signals in outlooks and the areas trending drier climatologically. Drought improvement/removal is likely across eastern New Mexico due to forecast above-normal precipitation during OND.

Forecast confidence is moderate for most of the West Region.

During the past month, drought conditions were little changed over the High Plains region. For most of this region - especially the western half of the Great Plains - OND is a transition toward the driest time of year. Currently, the most severe drought is located across Kansas and Nebraska, where D2 to D4 conditions are common in central and eastern parts of the region. Other areas of drought (D1 to D3) cover the northern sections of North Dakota and parts of southwestern Colorado.

Heavy precipitation is expected across eastern portions of the region over the next seven days, with enhanced chances for above-normal precipitation in October outlook in most southern locations, particularly in Nebraska and Kansas. Improvement/removal is likely across central-eastern Nebraska and Kansas. Given the lack of any indication of markedly wet weather during the period, and considering that October-December is a drier time of year, drought persistence is favored for existing drought over the Dakotas, Colorado and Utah during the next three months.

Forecast confidence in the High Plains region is low to moderate.

During the past four weeks, drought has expanded and intensified (1 to 4 class degradation) across much of Texas and Louisiana, southern portions of Oklahoma and Mississippi, where subnormal precipitation has been exacerbated by frequent periods of intense heat. In contrast, drought improvement/removal was observed over parts of southern Texas due to Tropical Storm Harold.

Over the next seven days, 1 to 5 inches heavy precipitation is expected across eastern Oklahoma and western Arkansas along with forecast above-normal precipitation over most of the region in the monthly and seasonal outlooks and a favorable time of year for soil moisture recharge, drought improvement/removal is favored for this region.

Forecast confidence in the South Region is moderate.

This is one of large areas covered by severe to exceptional (D1 to D4) drought. During the past four weeks, widespread drought expansion and development (1-2 class degradation) occurred across much of the Midwest due to episodes of extreme heat and dryness across the regions. Periods of heavy rainfall also reversed the trend of drought development across much of Michigan.

Drought persistence is favored for the north-western Midwest due to lack of a wet signal for the coming season and the areas trending to its climatological dry season. Drought improvement/removal is more likely across most of the southwestern Midwest due to expected heavy precipitation during the remainder of September and equal chances for below, near, or above-normal precipitation forecast during OND.

Forecast confidence in the Midwest is moderate.

Currently, most of the Southeast is free of drought with the worst conditions (up to D3) covering part of southwestern Alabama and the western Florida Peninsula. Elsewhere, only small, isolated patches of moderate to severe drought exist in northern and western Virginia, the Carolinas, and southwestern Alabama and the Florida Panhandle. OND is a favorable time of year for soil moisture recharge over much of this region, except for the Florida Peninsula entering its climatological dry season.

Over the next week, heavy rainfall amounts of 1 to 5 inches are anticipated in the southern and western Florida Peninsula, and the Mid-Atlantic coastal areas, along with enhanced chances for above-normal precipitation for the OND across the Southeast region. Drought improvement/removal is expected for the region.

Forecast confidence in the Southeast is moderate to high.

As in areas to the south, there is very little drought to be found in this region. Small patches of moderate drought are restricted to northeastern West Virginia, west-central Maryland and adjacent Pennsylvania, far western New York state and central coastal New Jersey. The OND is a favorable time of year for soil moisture recharge.

Over the next week, 1 to 5 inches heavy rainfall is expected across most of the coastal areas of this region along with the monthly and seasonal outlooks calling for either elevated chances of above-normal precipitation or equal chances of below, near, or above-normal precipitation over much of the region. Drought removal is expected for the entire region.

Forecast Confidence in the Northeast is moderate.

There is a small anomalous dry area (D0) in eastern Alaska. Alaska currently is drought free and is likely to continue as the region enters the cold season of the year and monthly and seasonal outlooks call for near to above-normal precipitation across the state.

Forecast Confidence in Alaska is high.

Drought has been expanding in Hawaii recently, and this trend is expected to continue across the entire Hawaiian Islands due to monthly and seasonal outlooks calling for below-normal precipitation over the state.

Forecast confidence in Hawaii is high.

Currently, there is a moderate drought in northwestern Puerto Rico. Drought removal is likely due to the dynamical model forecasts favoring above-normal rainfall.

Forecast confidence in Puerto Rico is low.

Drought has been a frequent occurrence for the past few years in the Virgin Islands, and as of late September, severe drought (D2) is designated for St John and exceptional drought (D4) for St Croix and St Thomas. Drought improvement/removal is likely due to the dynamical model forecasts favoring above-normal rainfall and late September, October, and November is a wet time of year.

Forecast confidence in the Virgin Islands is low.

Forecaster: Yun Fan

Next Seasonal Drought Outlook issued: October 19, 2023 at 8:30 AM EDT