Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 AM EDT Tue Apr 06 2021 Valid 12Z Tue Apr 06 2021 - 12Z Thu Apr 08 2021 ...Rain and the potential for severe thunderstorms are expected for the central U.S. for the next couple of days... ...Several inches of snow are possible in and around Wyoming and western South Dakota and Nebraska through tonight... ...Critical Risks of fire weather are in place for the Southwest and Southern High Plains through Wednesday... A surface low is forecast to slowly move across the central U.S. through Thursday, sweeping a cold front through the Southern/Central Plains and Mississippi Valley while a quasi-stationary front meanders across the the Upper Midwest. This system will produce widespread rain and thunderstorms over these areas, and thunderstorms could be severe. The Storm Prediction Center has delineated a Slight Risk of severe weather especially for hail and wind threats over the Central Plains today and tonight. Then on Wednesday, a Slight Risk of severe weather shifts to the Lower Mississippi and Tennessee Valleys, with a Marginal Risk stretching farther north. Additionally, the widespread rain and thunderstorms could produce 1 to locally 3 inches of rain for eastern South Dakota into the Upper Mississippi Valley near the stationary front through Thursday, and isolated flooding cannot be ruled out. Farther south, some areas in the Lower Mississippi and Tennessee Valleys could receive a couple of inches of rain on Wednesday and Wednesday night, which could cause flooding or flash flooding given the wet ground conditions, and there is a Marginal Risk of excessive rainfall in place there. Behind the surface low pressure system, the associated upper-level low will cause below normal temperatures and provide lift for snow to develop in the Northern/Central Rockies and High Plains through tonight. Higher elevations of the Wind River Mountains, Bighorn Mountains, and Black Hills could see 6+ inches of snow, while lower elevations of the Central Rockies and Central High Plains could see some snow, but lighter amounts. Winter Storm Warnings are in place for the Black Hills, while higher elevations of Wyoming and south-central Montana have Winter Weather Advisories in effect for this snow event. In the Southwest to Southern High Plains, warm temperatures are forecast along with gusty winds and low relative humidity values, and this combination will lead to the potential for dangerous fire weather conditions. A Critical Risk is outlooked by the Storm Prediction Center today, and widespread Red Flag Warnings are in effect as well. Elevated to Critical Risks are once again in place for much of New Mexico and West Texas on Wednesday. Warmer than average temperatures are expected for much of the contiguous U.S., with the exception of parts of the north-central U.S. underneath the upper low, and cooler temperatures spreading into the Northwest for midweek. The highest temperature anomalies are for the Great Lakes and Ohio Valley regions, with highs around 15 to 25 degrees above normal through Thursday. Elsewhere, Maine could continue to see light precipitation today on the backside of a lingering surface low pressure system in the Atlantic. The Northwest can expect increasing precipitation Wednesday into Thursday as another frontal system and additional upper-level energy comes in. Over a foot of snow is forecast for the Cascades for Wednesday into Wednesday night. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php