030 FXUS01 KWBC 190811 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Tue May 19 2026 Valid 12Z Tue May 19 2026 - 12Z Thu May 21 2026 ...Severe weather and flash flooding threats across east-central Plains to Midwest this morning will shift south into the Southern Plains and Ohio Valley later today into tonight... ...An early-season heatwave will challenge temperature records across the eastern U.S. through Wednesday... As a main piece of the upper-level trough ejects out of the central Rockies into the central Plains today, a slow-moving frontal boundary across the midsection of the country will begin to move farther to the south and east. This will allow the wet snow to end across the central Rockies, while the severe thunderstorms across east-central Plains this morning will shift farther south into the southern Plains later today. Scattered showers and thunderstorms ahead of a cold front will extend farther northeast across the Mid-Mississippi and Ohio Valleys, and into the lower Great Lakes through tonight. The greatest threat of flash flooding associated with these thunderstorms are forecast to be across central to eastern Texas as well as the Midwest/Ohio Valley through tonight. Meanwhile, an early-season heatwave is in full swing across the eastern U.S. A Bermuda High anchored over the western Atlantic will continue to bring a long fetch of warm southerly flow across the eastern half of the country, with high temperatures reaching into the mid-90s during the next couple of days. These temperatures will challenge or break temperature records across the east-central U.S. including the Mid-Atlantic, spreading into New England this afternoon. Widespread moderate to major HeatRisk is forecast for major cities across the I-95 corridor and into upstate New York today. In contrast, Frost and Freeze related Advisories/Warnings are in place into this morning across the northern/central Plains and into portions of the nearby Rockies behind the late-season snowfall. By Wednesday into Thursday morning, the cold front will make further eastward progress through New England but will begin to stall along the trailing end across Texas. Cooler temperatures behind the front will bring relief to the heat progressively through the eastern U.S. on Wednesday into Thursday morning, along with the arrival of scattered showers and some embedded thunderstorms. Meanwhile, thunderstorm and heavy rain chances will nudge farther into western Texas later on Wednesday into Thursday morning as the front becomes stationary. Meanwhile, remaining upper troughing in the West will bring some light high-elevation snow and lower-elevation showers and storms to Colorado through the next couple of days. Showers and some embedded thunderstorms will be developing and expanding across Montana Wednesday night with the arrival of an upper trough from western Canada. Florida could see slight increase in thunderstorm chances as a disturbance edges closer toward the Bahamas. The West Coast will remain dry apart from some showers moving onshore into Washington state. Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$