Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 AM EDT Tue Apr 27 2021 Valid 12Z Tue Apr 27 2021 - 12Z Thu Apr 29 2021 ...There is a Slight risk of Severe Thunderstorms over parts of the Southern/Central Plains through Wednesday morning... ...Fire danger narrows to the Southern /Central High Plains Wednesday... ...Temperatures will be 10 to 15 degrees above average from the Middle Mississippi Valley eastward to the Mid-Atlantic, while Temperatures will be 10 to 20 degrees below average over the Southwest... A wave of low pressure over the Central Plains will move eastward to the Ohio Valley by Thursday as the trailing front lingers over the Southern Plains. Showers and thunderstorms will develop along and ahead of a dryline over the Central/Southern Plains on Tuesday evening into Wednesday. The SPC has issued a Slight risk of severe thunderstorms over parts of the Southern/Central Plains through Wednesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. There is a 10% or greater probability of two-inch or larger diameter hail with the severe thunderstorms. The heavy rain associated with the thunderstorms may produce isolated areas of flash flooding. Furthermore, showers and thunderstorms will develop along and north of the boundary from the Central/Northern Plains into the Upper Great Lakes on Tuesday into Tuesday evening. Overnight Tuesday, the showers and thunderstorms will expand into parts of the Lower Great Lakes and into parts of the Northeast by Wednesday morning. Additional severe weather may develop over parts of the Southern Plains on Wednesday. The showers and thunderstorms will slowly move into parts of the Middle/Lower Mississippi Valley by Wednesday morning while lingering over parts of the Southern Plains. Meanwhile, an upper-level low over the Great Basin will move eastward to Texas while weakening by Thursday. The system will produce rain and snow over parts of the Pacific Northwest to the Northern Rockies southward to the Great Basin, Southern California, and the Southwest on Tuesday. The rain and snow will end over the Northwest by Tuesday afternoon, while the rain and snow will move into parts of the Central Rockies. The rain and higher elevation snow will move into parts of the Southern Rockies by Wednesday morning. The rain and snow will end over the Central/Southern Rockies by Thursday morning. While the weather will relieve the fire weather threat over the Southwest and Southern Rockies, a Critical and Elevated fire weather threat will continue over the Southern/Central High Plains into Wednesday morning. Elsewhere, under the upper-level low temperatures will be 10 to 20 degrees below average over the Southwest. The temperatures will be 10 to 15 degrees above average from the Middle Mississippi Valley eastward to the Mid-Atlantic on Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php