Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 428 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 still 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. The plentiful cloud cover will keep temperatures near or slightly below normal across much of the Southern Plains. On the cold side of the system, the mountain snow over the northern Rockies should slowly wind down later today as the storm will begin to move eastward tonight across south-central Canada and intensify further. This will bring gusty winds across the northern Plains into tonight. Over the Great Lakes, a warm front will push warm and humid air into the region. Meanwhile, cooler air from New England will push southward through the Mid-Atlantic states today behind a back-door cold front. Some thunderstorms could develop across the Mid-Atlantic today as a low pressure wave moves along the frontal boundary. By Tuesday night, warm air will try to sneak back in across New England behind a warm front. Meanwhile, moisture from the next system in the Pacific is expected to push into the Pacific Northwest today. This system could help organize another round of wet snow across the northern Rockies by late Tuesday into Wednesday morning. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php