Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) temperature and precipitation outlooks for March 2020 and March-April-May (MAM) 2020, various short-range 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), the Weeks 3-4 outlooks and tools from CPC, dynamical models at the monthly and seasonal time scales, climatology for the MAM season, snow cover, soil moisture, and initial conditions. ENSO conditions are favored to remain neutral during the boreal spring season.
Drier than normal conditions persist across much of the Western Region. Below-normal precipitation is favored in the Pacific Northwest in the ERF, Weeks 3-4, and March precipitation outlooks, with equal chances to below-normal favored for the MAM season. Precipitation over California is favored to be below-normal through MAM. As such, drought persistence is expected in central Washington, north-central Oregon, and central California. Drought expansion is expected across central and northern California, Oregon, and eastern Washington. Snowpack in the Cascades is slightly above normal, so no development is expected along the eastern slopes in Washington. Drought development in California is supported by an increasing potential for a dry end to their climatological wet season. Drought Persistence in Idaho is status quo for now also, as long-range outlooks for this region favor near-normal precipitation. The long-term drought over the Four Corners region is expected to persist, with slight southward expansion likely due to drier than normal conditions over the past 30-60 days over Arizona and northern parts of New Mexico. However, wet antecedent conditions in southwestern New Mexico over the last 30 days make it more unlikely for any further southward expansion into the state.
Forecast confidence is low for the Pacific Northwest, and moderate for the Southwest (West Region).
Drought persistence is likely in the southwestern High Plains Region (near the Four Corners region) due to the lack of a clear wet signal during the MAM period. Drought removal is likely for central Kansas over the next couple of weeks in association with enhanced probabilities of above-normal precipitation over this region through the Week 2 period, with equal chances favored for MAM. In addition, severe weather may start to play a role in the April to May timeframe, which further supports removal there. No drought development is expected.
Forecast confidence is moderate for the Four Corners region, and high elsewhere for the High Plains Region.
Much of the Midwest region is seeing 1-2 inch positive precipitation anomalies for the past 90 days, with pockets of 4-inch positive anomalies near the Great Lakes. A larger area of greater than 4-inch positive anomalies in southern portions of the region stretches from Missouri eastward to the Ohio Valley. Although below-normal precipitation is favored in the first month of the MAM period, above-normal precipitation is favored for much of the region later in the period, with the highest probabilities centered over the Ohio River Valley. Based on these wet antecedent conditions and the wet Spring outlook, no drought development is anticipated. In fact, these are some of the same areas that had a late start to the 2019 growing season due to excessive rainfall, so agricultural impacts from potential excessive rainfall will need to be monitored closely.
Forecast confidence is high for the Midwest Region.
Heavy rainfall in central and eastern Texas in recent days (in excess of 6 inches locally) has removed much of the deficit across central portions of the state. With above-normal precipitation expected over the next couple of weeks in association with the potential for lee-side cyclogenesis and trailing frontal boundaries, short-term improvement and removal are favored for areas north of the I-10 corridor between Houston and San Antonio. Meanwhile, drought conditions are favored to persist south of the I-10 corridor, extending from interior areas of the Gulf Coast westward to the Rio Grande Valley. Some drought development is favored in western Texas due to consistent dry signals in the models. Drought removal is favored in southwestern Oklahoma, as the severe weather season climatologically begins during the latter half of the period, and drylines tend to set up near this region.
Forecast confidence is low for Texas, and moderate elsewhere for the South Region.
Long-term drought over the Florida Panhandle (near Tallahassee) in the Southeast Region continues (365-day deficits of ~20 inches in localized areas), but is favored to improve for locations with long-term deficits, and to dissipate for those in short-term drought, with above-normal precipitation favored for all forecast periods. In addition, drier than normal conditions over the Big Bend and portions of the peninsula are expected to also improve, with no additional drought development likely. The rest of the region is expected to remain wetter than normal.
Forecast confidence is moderate for the Florida Panhandle, and high elsewhere for the Southeast Region.
The Northeast region as a whole remains near normal for observed year-to-date precipitation. Weak negative anomalies have crept into coastal areas of New England, but have not been significant enough to warrant any development yet. In addition, weakly positive probabilities for above-normal precipitation are favored for MAM. As such, no drought development is expected for the Northeast during the MAM period.
Forecast confidence is high for the Northeast Region.
Drought in the Alaska Panhandle has dissipated over the past 30 days due to an active storm track across the state. Above-normal precipitation is favored over the panhandle over the next 2 weeks, with weak probabilities for below-normal precipitation favored for the MAM period. However, dry precipitation signals in the models have weakened a bit in recent days over the panhandle. In addition, above-normal precipitation is favored for much of Mainland Alaska through the period. No drought development likely for the state.
Forecast confidence is moderate for Alaska.
Drought improvement or removal is likely in Hawaii. Models favor moderate probabilities for above-normal precipitation during the period. No drought development is expected.
Forecast confidence is high for Hawaii.
A small area of northwestern Puerto Rico remains drier than normal, with 30-day rainfall deficits of 1-3 inches, despite the rest of the island being anywhere from near normal to 5 inches above normal. Models are showing weak precipitation signals for this region. For now, no development is expected.
Forecast confidence is moderate for Puerto Rico.
Forecaster: Adam Hartman
Next Seasonal Drought Outlook issued: March 19, 2020 at 8:30 AM EDT