875 FXUS01 KWBC 090808 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Wed Sep 09 2026 Valid 12Z Wed Sep 09 2026 - 12Z Fri Sep 11 2026 ...Heavy rain and severe weather threats will spread from the Midwest this morning to interior New England tonight... ...Persistent heat across the south-central U.S. is forecast to get a break on Thursday.... ...Showers and thunderstorms will stretch across the Central Plains to the Mid-Atlantic over the next couple of days with locally heavy rain across the central Appalachians on Thursday... A large high-pressure system sliding off the East Coast will give way to an expanding and intensifying low pressure system currently tracking east across southern Canada. The recent episode of fine and cool late-summer weather will give way to a resurgence of heat across much of the eastern U.S. Meanwhile, the cyclone in southern Canada will sweep a cold front through the northern tier states over the next couple of days. Areas of heavy rain and severe weather threats near and ahead of the front will spread from the Midwest and the lower Great Lakes this morning to interior New England by tonight. As the frontal system pushes against the persistent heat dome across the South, expect a stretch of showers and thunderstorms from the Central Plains through the Mid-Atlantic over the next couple of days. Locally heavy rain is possible across the Mid-Mississippi Valley today, followed by the central Appalachians on Thursday when a couple of low pressure waves form along the front losing forward momentum. This front will also break the unrelenting heatwave across the south-central U.S. by Thursday, bringing clouds, occasional rain, and some embedded thunderstorms. Meanwhile, monsoonal moisture will continue to support mainly late-day showers and thunderstorms across Arizona and New Mexico. Some thunderstorms with heavy rain will also extend north into Colorado today in connection with the southern end of the frontal system trailing from the Canadian cyclone. WPC highlights a Slight Risk (level 2/4) of excessive rainfall over southeastern Arizona into southwestern New Mexico for today into this evening. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, low-lying areas, and burn scars being the most vulnerable. Elsewhere, showers and thunderstorms will linger across the Southeast U.S. closer to the coast and including Florida near a dissipating front. On the opposite side of the country, fine and dry weather will prevail across the Northwest before the next chance of showers reaches the Pacific Northwest by Thursday as a cold front approaches from the northwest. Kong/Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php Extreme Heat Key Messages available at: https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png $$