Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Mon May 24 2021 Valid 12Z Mon May 24 2021 - 12Z Wed May 26 2021 ...Late-season snow across the northern Rockies slowly winding down today but resuming Tuesday night... ...Scattered thunderstorms through the Plains could produce locally heavy rains, isolated flash flooding with possible severe weather... Another round of mountain snow is currently in progress across the northern Rockies as a low pressure system intensifies over the northern Plains and lifts quickly northward into the Canadian prairies today. Strong to severe thunderstorms will accompany the sharp trailing cold front across the northern and central Plains early this morning. But as the main energy of the low pressure system lifts into Canada, there is a tendency for the thunderstorms to become weaker during the next couple of days. However, the stream of tropical moisture from the Gulf remains open for the next couple of days. Scattered thunderstorms could still produce locally heavy rains, isolated flash flooding with possible severe weather over parts of the central and southern Plains into Wednesday morning. On the cold side of the system, more mountain snow is falling today over the northern Rockies. Monday into Tuesday, the storm will migrate into south-central Canada but the warm front will surge north across the Great Lakes and lead to high temperatures to surge into the high 80s and possible low 90s by Tuesday over the central Great Lakes, but even high 70s across far northern MN and the U.P. of Michigan too. The strong ridge over the Ohio/Tennessee Valleys into the South will support anomalously high temperatures too, with some highs into the high 90s by Tuesday across AL, GA and SC. Across the Northeast, a cold front will drop through later today and bring a break to the Northeast and coastal Mid-Atlantic with highs below average on Monday. In the crossroads between the Great Lakes/Northeast, there is a threat for repeat overnight thunderstorms that may bring excessive rainfall and potential for scattered flash flooding concerns across the Allegheny Plateau and Allegheny Mountains, where complex/rolling terrain channels water toward flooding concerns faster. Similar stormy conditions will expand into southern Mid-Atlantic and North Carolina Monday into Tuesday. The deep tropical moisture feed/atmospheric river along the southwest portion of the strong Eastern U.S. Ridge remains directed at the central Texas coast, but it appears to be reducing toward Tuesday and later in the week. Still, threat of scattered thunderstorms across saturated grounds, still poses a Slight Risk of Excessive Rainfall across the Central Texas Coast today, but a Marginal Risk remains for Monday. If there is one benefit of the deeper moisture; is the cloud cover reducing overall temperatures to near or slightly below normal across much of the Southern Plains. Kong/Gallina Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php