Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 322 PM EDT Sun May 16 2021 Valid 00Z Mon May 17 2021 - 00Z Wed May 19 2021 ...Severe thunderstorms likely across portions of the Central and Southern Plains through Tuesday... ...Areas of flash flooding possible tonight and Monday across the central and south-central United States, with a greater risk of excessive rainfall on Tuesday from southeast Oklahoma to north-central Texas... The most important weather story over the next few days will continue to be found across central and south-central sections of the country, where continuing rounds of heavy rain and thunderstorms will impact the region. The atmospheric ingredients responsible for this weather pattern include a quasi-stationary boundary that extends from the Central Rockies through the Central Plains and into the Lower Ohio Valley. Meanwhile, an upper-level low spinning above the Southwest will allow for replenishing moisture from the western Gulf of Mexico to surge northward. A dryline located across the southern High Plains will also help spark thunderstorm activity. A few storms may turn severe tonight and Monday across the central and Southern High Plains. The Storm Prediction Center has issued a slight risk (level 2 of 5) of severe weather for this evening across the aforementioned region, with an enhanced risk (level 3 of 5) valid on Monday across portions of the Texas Panhandle. Damaging wind gusts, large hail, and isolated tornado are all a possibility. Additional rounds of severe weather are possible across the Southern Plains on Tuesday. Along with the threat of severe weather, heavy rain could pose a significant threat of flash flooding by Tuesday after multiple rounds of downpours tonight and Monday. WPC has issued a Slight Risk of Excessive Rainfall through early Monday morning across eastern Kansas and northern Missouri, south-central Oklahoma and north-central Texas, as well as coastal sections of southeast Texas. Multiple days of rainfall will likely lead to saturated soils and conditions ripe for flash flooding. By Tuesday afternoon and evening, an additional impulse of thunderstorms could dump over three inches of rain from southeast Oklahoma to northeast and north-central Texas. This amount of rain will likely lead to flash flooding across this area. Therefore, WPC has issued a Moderate Risk of Excessive Rainfall for Tuesday. Flash Flood Watches are also in effect through Tuesday night. Elsewhere, scattered showers and high elevation snow are possible across the Pacific Northwest on Monday and Tuesday as a cold front enters the region. Outside the Northwest, above average temperatures will be found across the Northern Tier to start the workweek. This will includes highs in the 70s and 80s stretching from the Northern Rockies through the Upper Midwest and into New England. For the Southwest, dry and windy conditions will continue to lead to fire weather concerns. Wind Advisories are in effect across interior southern California, with Red Flag Warnings found across southern Utah and southeast Arizona. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php