Tools used in the U.S. Seasonal Drought Outlook (SDO) include the Climate Prediction Center (CPC) seasonal precipitation and temperature outlooks for April-May-June (AMJ), monthly precipitation and temperature outlooks for April, 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, dynamical model output, AMJ climatology, and initial conditions such as snowpack and soil moisture. The U.S. Drought Monitor, valid on March 14, was used for initial drought conditions. La Niña recently ended and ENSO-neutral conditions are expected to continue through the spring and early summer.
Drought improvement or removal is forecast across much of California and the Great Basin, based on above-normal precipitation for the water-year-to-date (WYTD) from October 1, 2022 to March 14, 2023 along with snow water equivalent (SWE) of more than 150 percent of normal, and a continued wet pattern forecast for the latter half of March. 7-day (March 15 to 21) QPF from WPC exceeds 2 inches, liquid equivalent, across the Sierra Nevada Mountains. The 8-14 day precipitation outlook favors above-normal precipitation across California and the Great Basin. SWE is running more than 200 percent of normal across the water basins of central California and much of Nevada. From December 1, 2022 to March 13, 2023, Reno, Nevada has recorded 10.06 inches of precipitation which is 265 percent of normal. The wet 2022-2023 winter, with multiple atmospheric river events, led to the following California reservoirs to reach or exceed their historical average: Oroville, New Bullards Bar, Folsom, Camanche, Don Pedro, McClure, Pine Flat, Millerton, Cachuma, San Luis, and Sonoma. However, the Trinity and Shasta reservoirs in northern California are at 47 and 87 percent of their historical average, respectively. It should be noted that Lakes Mead and Powell remain low.
Much of the Pacific Northwest received below-normal precipitation since the beginning of October 2022 with 28-day streamflows below the 25th percentile across Washington and below the 10th percentile for northeast Oregon and northern Idaho. Although the pattern is forecast to become wetter during the final week of March, the initial dryness heading into the spring and the AMJ outlook favoring below-normal precipitation support persistence and the slight expansion of drought for the Pacific Northwest. This persistence also extends east to western Montana, but an increasingly wet climatology during the spring supports improvement/removal for the eastern two-thirds of Montana. Above-normal snowpack over the Four Corners region is expected to limit the chances of development, despite the favored dryness in the AMJ outlook. Southern and eastern New Mexico have missed out the abundant precipitation this past winter. This is reflected in a sharp gradient in soil moisture percentiles from west to east across New Mexico. Given the increased probabilities for below-normal precipitation and above-normal temperatures during AMJ, development is likely for eastern and southern New Mexico by the end of June.
Forecast confidence for the Western Region is moderate.
Precipitation surpluses, dating back 90 days, and an increasingly wet climatology during the spring support improvement or removal of drought across the northern Great Plains. 40 to 45 percent of the annual precipitation typically occurs during AMJ across the Dakotas. The highest confidence for removal exists across the eastern Dakotas due to a deep snowpack which will eventually melt and help to replenish soil moisture. A wet spring climatology also favors removal or improvement for eastern Wyoming, Nebraska, northeastern Colorado, and northern to eastern Kansas. Persistence or development is more likely for southwestern Kansas and southeastern Colorado with elevated probabilities for below-normal precipitation in the AMJ outlook. Widespread extreme (D3) to exceptional (D4) drought is designated for southwestern Kansas and this intense drought is expected to continue into the spring.
Forecast confidence is high for the eastern Dakotas and moderate for the remainder of the High Plains Region.
Widespread severe (D2) to exceptional (D4) drought continues for much of the southern Great Plains. Soil moisture is below the 5th percentile across northwest Oklahoma along with the Oklahoma and Texas Panhandles. With this multi-year drought, little to no precipitation forecast during mid to late March, and the AMJ outlook favoring below-normal precipitation and above-normal temperatures, persistence is forecast for the western third of Oklahoma and west-central Texas. Development is expected by the end of June for current drought-free areas of western Texas. Removal is forecast along parts of the Texas and Louisiana Gulf Coast due in part to heavy precipitation forecast during the next week, and this upcoming wetter weather is likely to reduce 30-day precipitation deficits for lower Mississippi Valley. Eastern Oklahoma, the Ozarks Region, and the Tennessee Valley have been quite wet since mid-February and soil moisture is above the 90th percentile for many areas. However, it should be noted that these areas can dry out quickly during the early summer if multiple weeks of dryness and excessive heat occur. As we move closer to the early summer, this region will be closely monitored for the potential rapid onset of drought.
Forecast confidence is high for the Southern Region.
30-day precipitation has averaged more than 150 percent of normal throughout the Midwest and at or above 300 percent of normal for eastern Minnesota and parts of Wisconsin. Only western Minnesota, western Iowa, and southern Michigan are designated with drought and improvement or removal is forecast with near to above-normal precipitation favored through late March and with the AMJ outlook leaning wet or calling for equal chances of below, near, or above-normal precipitation. Also, spring is a relatively wet time of year for the middle to upper Mississippi Valley.
Forecast confidence is high for the Midwest Region.
The drought coverage and intensity may be peaking across Florida as a pattern change is likely to result in wetter weather and much cooler temperatures during the next week. The WPC 7-day QPF depicts widespread 1.5 to 3 inches of rainfall throughout the Sunshine State. This anomalous wetness for this time of year is associated with a strong cold front on March 17 and 18, followed by surface low development over the Gulf of Mexico. This short-term rainfall could lead to drought improvement/removal for Florida or at least prevent worsening drought conditions through late March. Although drought status is more uncertain during April and May, the increasingly wet climatology with sea breeze convection during June favors removal throughout Florida by the end of June. The remainder of the Southeast is expected to remain drought-free through June, but this region will be closely monitored for any potential rapid onset of drought as temperatures warm later this spring and into the early summer. Removal is forecast for the small drought area in southeastern Virginia, based on precipitation during the remainder of March and the lack of a dry signal at the seasonal time scale.
Forecast confidence is moderate for the Southeast Region.
The Northeast became drought-free at the beginning of February and is expected to remain drought-free through the end of June. Recently, a major Nor'easter resulted in heavy snowfall across parts of New York and New England which had been quite dry during February. Although only light precipitation is expected during the next week, the 8-14 day outlook favors above-normal precipitation and the AMJ outlook either leans wet and calls for equal chances of below, near, or above-normal precipitation. Despite recent declining soil moisture and low 28-day average streamflows for parts of the Mid-Atlantic, forecast confidence is too low to forecast development likely for this region given the lack of a predicted dry signal among precipitation tools through the next 3.5 months.
Forecast confidence is moderate for the Northeast Region.
Based on near or above-normal snow water equivalent values throughout the river basins of Alaska, drought is unlikely to develop by the end of June.
Forecast confidence is moderate for Alaska.
A Kona low contributed to a wet February throughout Hawaii. The state became drought-free during early February. Based on the wet antecedent conditions and since the AMJ outlook calls for equal chances of below, near, or above-normal precipitation, development is unlikely for Hawaii.
Forecast confidence is high for Hawaii.
According to the Advanced Hydrologic Prediction Service (AHPS), 30-day precipitation deficits range from 2 to 4 inches across northwestern and eastern Puerto Rico. A few 28-day average streamflows have dropped below the 10th percentile in eastern Puerto Rico. Due to the lack of a wet signal at any time scale during the next 3.5 months, development (persistence) is forecast for parts of Puerto Rico that are currently designated with abnormal dryness (moderate drought) in the USDM.
Forecast confidence is moderate for Puerto Rico.
Forecaster: Brad Pugh
Next Seasonal Drought Outlook issued: April 20, 2023 at 3PM EDT