584 FXUS01 KWBC 201947 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 346 PM EDT Thu Aug 20 2026 Valid 00Z Fri Aug 21 2026 - 00Z Sun Aug 23 2026 ...Severe weather and flash flood threats across parts of the East into tomorrow, with severe threats over the Central Plains on Friday... ...Dangerous heat persists in the South while building into the Southwest... A couple of wavy cold front in the East will support and help focus heavy rain, flash flooding, and severe weather across much of the Mid-Atlantic this evening and into tonight. As daytime heating and instability are maximized this afternoon, strong to severe weather with embedded heavy rain will focus along a slow moving boundary draped across the Mid-Atlantic. WPC highlights this region with a slight risk of excessive rainfall. There an embedded moderate risk for excessive rain/flash flooding for the New York City metro region and central to northern New Jersey where an area of low pressure exiting the coast could help to enhance rainfall in this more flood prone region. The northern part of this boundary should shift off the Coast later tonight, but the southern portion should help to maintain the severe weather and flash flood threat across the southern Mid-Atlantic and parts of the Carolinas tomorrow. Both WPC and SPC highlight this region in the respective excessive rainfall and convective outlooks for Friday. Over the midsection of the country, another round of severe weather is possible for eastern Nebraska into Minnesota and Wisconsin this afternoon into the evening ahead of a front trailing from a low pressure wave moving across Minnesota into the U.P. Michigan. SPC has outlined a slight risk of severe weather for the area where the main threat will be large hail, and isolated wind damage. On Friday, much of central and eastern Nebraska will experience another round of severe weather as the trailing front pushes southward. SPC highlights this region in a slight risk. As this boundary is expected to be rather progressive, flash flooding is not a threat, but heavier rainfall is possible in stronger thunderstorms. Meanwhile, monsoonal showers and thunderstorms will be most active during the late-day hours across the Four Corners states, where the WPC has highlighted a marginal risk of Excessive Rainfall through the next couple of days. The southern tier of the Lower 48 remains mired in a steamy air-mass even by mid-to-late August standards. Record highs and record warm minimum temperatures will be common from the Southern Plains into the Southeast, with a few records into the Southwest as well. Extreme Heat Warnings are in effect for much of the Desert Southwest, with Extreme Heat Warnings and Heat Advisories extending from the Southern Plains to Florida and the Southeast Coast. Expect little to no overnight relief across these regions as temperatures struggle to get below 80F in some locations. This equates to widespread Major to Extreme HeatRisk. The heat should finally moderate across the Southeast as a cold front moves into the region on Friday, but this potentially dangerous heat wave will continue even beyond the short range period for the Southern Plains and expand over the Southwest as well. Please refer to Key Messages issued by WPC for additional information on this event. Santorelli/Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$