Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 PM EDT Mon May 10 2021 Valid 00Z Tue May 11 2021 - 00Z Thu May 13 2021 ...There is an Enhanced Risk of severe thunderstorms over parts of south-central Texas through Tuesday morning... ...There is a Slight Risk of excessive rainfall over parts of the Tennessee/Lower Mississippi Valleys and the Southern Plains through Wednesday morning... ...Late-season snowfall is likely across the Northern/Central Rockies and High Plains with much colder than average temperatures... ...Warm and dry conditions will cause fire danger in the southwestern U.S. and California... A front extending from the southern Mid-Atlantic southwestward to the Central Gulf Coast, then westward into the Southern Plains will be quasi-stationary through Wednesday. The boundary will move off the Central/Western Gulf Coast into the Gulf of Mexico by Wednesday evening. The system will produce severe thunderstorms and heavy rain over parts of the Southern Plains and the southern Mid-Atlantic through Tuesday morning. The SPC has issued an Enhanced Risk of severe thunderstorms over parts of south-central Texas a Slight Risk of severe thunderstorms over the Ark-La-Tex and the southern Mid-Atlantic through Tuesday morning. The hazards associated with these severe thunderstorms are frequent lightning, severe thunderstorm wind gust, hail, and a few tornadoes. Some of the storms will have a 10% or greater probability of producing hail two inches or greater over parts of south-central Texas through Tuesday morning. The thunderstorms will also produce heavy rain. The showers and thunderstorms over the southern Mid-Atlantic/Southeast will move off the coast overnight Monday. The showers and thunderstorms will continue over the Southern Plains and the Lower Mississippi/Tennessee Valleys on Tuesday. Due to the heavy rain over the region, the WPC has issued a Slight risk of excessive rainfall over parts of the Tennessee/Lower Mississippi Valleys and the Southern Plains through Wednesday morning. The hazards associated with the rain are scattered flash flooding, where urban areas, roads, and small streams are the most vulnerable. On Tuesday evening and into overnight Tuesday, the showers and thunderstorms will return to the Southeast and continue through Wednesday evening. Also, on Wednesday, the showers and thunderstorms over the Southern Plains will retreat to the Gulf Coast by Wednesday evening. Meanwhile, energy from a weakening upper-level low over the Great Lakes will move over the Northeast. Rain will develop over parts of the Upper/Middle Mississippi Valley and the Great Lakes overnight Monday, ending by Tuesday morning. On Tuesday, the rain will develop over parts of the Northeast, continuing into Wednesday evening. Furthermore, upper-level energy and cold temperatures will lead to snow across the Northern and Central Rockies late Tuesday night. Temperatures are expected to be below average for much of the country behind the potent cold front, especially by Tuesday. High temperatures in the central parts of the High Plains will be around 30 degrees below average for this time of year. Freeze Warnings and Frost Advisories are in effect for portions of the Great Lakes and Ohio Valley and Middle/Upper Mississippi Valley through Tuesday morning in terms of cold low temperatures. In contrast, temperatures will be warmer than average over the West Coast, especially California. The warm temperatures and dry and windy conditions have led to Elevated and Critical Risks of fire weather and Red Flag Warnings in interior Northern California and the Southwest/Southern Rockies/Southern High Plains through Tuesday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php