Tools used in the U.S. Monthly Drought Outlook (MDO) included the updated Climate Prediction Center (CPC) temperature and precipitation outlooks for February, 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), experimental weeks 3-4 outlooks, CFSv2 model forecasts, the 384-hour total precipitation forecasts from several runs of the GFS, climatology, and recent precipitation.

As of January 30 following an extremely wet January, California reservoir storage is at just over 110 percent of normal for the time of year, according to the California Department of Water Resources. Snow Water Equivalent (SWE) values are at 177 percent of normal statewide (and already higher than the April 1st average), and over 200 percent of normal across the southern Sierras. These conditions, in addition to widespread heavy rainfall across coastal areas and the Central Valley, resulted in widespread drought reductions across the state. As of the January 26 U.S. Drought Monitor, only 2.16 percent of California's land area was considered to be in extreme (D3) drought, compared to 42.8 percent at the start of the water year, and 63.96 percent a year ago. During the past 4 weeks, drought improvements were also noted across much of Nevada, Arizona, Utah, and New Mexico. During early February, yet another major storm system is expected to bring widespread heavy rainfall and mountain snows to the Northwest and California. The latest 7-day QPF forecast from the Weather Prediction Center (WPC) shows a potential for up to 5 inches as far south as Monterey County, with an additional 3 to 10 inches liquid equivalent snowfall across the Sierras. This early month event should be sufficient to continue the drought reduction trend across California, although the southern coastline, desert regions , and Nevada will likely miss out on the heavier precipitation. Following this heavy precipitation event, a dry, unseasonably warm pattern is anticipated to build across much of the Southwest. While the pattern change may limit further improvements during mid-February and may promote some snowmelt, substantial change to recent drought tendencies is unlikely. Beyond Week-2, longer range models are mixed, with the CFS depicting a return to heavy precipitation across all of California, and the ECMWF limiting the heavier precipitation to northern California. The CPC February monthly outlook shows equal chances for below-, near-, and above-median precipitation. Based on the ample snowpack and reservoir levels to start the month and the wet short term forecast, therefore, improvement is anticipated across California's central coast, the Central Valley, and the Sierras. Persistence is favored for southern California and the remaining drought areas across Arizona, New Mexico, and Nevada.
Forecast confidence for the West is moderate to high.

Widespread precipitation across the Rockies and High Plains resulted in drought reductions from eastern New Mexico and North Texas northward to eastern Montana, while drier conditions across the Great Plains and Midwest resulted in drought intensification or development across much of Oklahoma, northwestern Arkansas, and Missouri. Drought development also occurred across far south Texas. During the next 7 days, a wet pattern is anticipated across the northern Plains, while a winter storm is anticipated to bring moderate to heavy precipitation from northeastern Texas and eastern Oklahoma across the Tennessee Valley. In contrast, dry conditions are forecast for much of the central and southern Plains. A similar pattern is anticipated during Week-2, with the CPC 8-14 day outlook depicting enhanced chances for below- (above-) median precipitation across the central and southern Plains (northern Plains and Midwest). The CPC February outlook also depicts enhanced chances for below-median precipitation across the southern Plains, with above-median precipitation favored across the northern Plains and Ohio Valley. Based on these outlooks, drought persistence is generally favored from eastern Colorado through northern Arkansas and Missouri, while improvements are anticipated across the northern Plains. The best chances for drought reductions are along the Mississippi River. Based on recent dryness and a clear dry and warm signal in the guidance at all time scales, drought expansion is favored across South Texas.
Forecast confidence for the Plains and Midwest is moderate.

From January 21-23, a slow moving area of low pressure generated widespread heavy rainfall across the Southeast, with at least 2 inches across all of the drought areas, and 4 to 8 inches falling across southern Georgia and northern Florida. The rainfall resulted in widespread drought reduction, but the storm system also produced 77 tornadoes, which caused 20 deaths and extensive property damage. During the next week, a winter storm is forecast to bring an additional 0.5 to 1.5 inches of precipitation across northeastern Texas through North Carolina. This precipitation should continue to engender drought improvement, particularly across the Piedmont and southern Appalachians. The CPC 6-10 and 8-14 day outlooks both favor above-median precipitation, while the February outlook depicts equal chances for below-, near-, and above-median precipitation. Based on these outlooks, drought amelioration is favored across the Southeast Piedmont region and the southern Appalachians. There is reduced confidence for improvement across the coastal Plain, based on less precipitation in the short term forecast, and a similar pattern in the 384hr GFS total precipitation guidance. Additionally, based on increasing rainfall deficits, drought development is anticipated across south-central Florida, excluding the Keys, Everglades, and the Broward/Dade metropolitan areas.
Forecast confidence for the Southeast is moderate.

Near-normal January precipitation across the Northeast has generally favored drought improvement, with reductions observed across parts of Maine, eastern Massachusetts, Long Island, northern New Jersey, and parts of upstate New York and central Pennsylvania. Precipitation deficits persisted, however, across southeastern Pennsylvania and southern Maryland and Delaware, resulting in expansion of drought and abnormal dryness. During the next 7 days, the WPC QPF forecast depicts a quarter to half-inch of precipitation across much of New England, with a potential for bands of lake effect snowfall to set up east of the Great Lakes. Smaller accumulations (below a quarter-inch) are anticipated across the mid-Atlantic region, including central Maryland and southeastern Pennsylvania. The CPC 6-10 and 8-14 day outlooks both favor enhanced chances for above-median precipitation across the entire region, while the February outlook maintains equal chances for below-, near-, and above-median precipitation along and east of the Appalachians. Based on both the anticipated short term precipitation and the CPC ERF guidance, drought improvements are forecast for much of the Northeast; however, persistence is indicated across Maryland, southeastern Pennsylvania, and along the Delaware River, based both on incipient precipitation deficits and a weaker wet signal in the guidance.
Forecast confidence for the Northeast is low to moderate.

Small areas of drought continue to linger along the leeward side of several islands in Hawaii. During early February, a frontal system is anticipated to bring heavy precipitation and southwesterly flow to northwestern Hawaii, which favors removal of drought on the lee side of Kauai. Following this system, however, longer range guidance generally favors near to below-median precipitation. Therefore, drought persistence is maintained elsewhere. There is no drought currently indicated on the USDM across Alaska and Puerto Rico, and drought is not anticipated to develop across these regions during February.
Forecast confidence for Hawaii is moderate.

Forecaster: Adam Allgood

Next Monthly Drought Outlook issued: February 28, 2017 at 3pm EST