571 FXUS01 KWBC 292014 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Sat Aug 29 2026 Valid 00Z Sun Aug 30 2026 - 00Z Tue Sep 01 2026 ...Strong to severe thunderstorms possible across parts of the Great Basin into tonight... ...Strong thunderstorms expected to move across the Northern Plains later on Sunday... ...Slight Risk of excessive rainfall across the Four Corners region Sunday and Monday... A more active weather pattern is expected to develop across the western U.S. as a couple of upper-level low/troughs are forecast to move through the region. Showers and embedded thunderstorms ahead of the leading trough have already triggered across the Four Corners states into southwestern Wyoming this afternoon. The Storm Prediction Center is highlighting the vicinity of northern Utah as most susceptible to a slight risk of severe thunderstorms through tonight. ÂIn addition, WPC is highlighting a slight risk of excessive rainfall across the northern Great Basin and portions of Arizona through tonight. ÂThe associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, narrow canyons/gullies, and burn scars being the most vulnerable. From Sunday into Monday, the next upper-level trough is forecast to move onshore across California toward the Great Basin. This more subtle trough could become more amplified and bring a higher chance of more widespread showers and thunderstorms for the Four Corners states. Therefore, WPC has expanded the slight risk of excessive rainfall for this region for both days. Areas of heavy rain may lead to localized rapid runoff from streams leading to flash flooding. Meanwhile, fine and cooler-than-normal temperatures for late August have overspread the entire northeastern quarter of the country behind a cold front. The trailing portion of the front will remain nearly stationary across the Southeast, where showers and thunderstorms are expected to be most active during the late-day hours with localized flooding possible. A weak low-pressure area just off the central to eastern Gulf Coast will also maintain a good chance of showers and thunderstorms nearby for the next couple of days. Showers and thunderstorms can be expected to be most active in the late-day hours across the Sunshine State. The trough moving through the Pacific Northwest will first bring showers and embedded thunderstorms from west to east closer to the Canadian border for the remainder of this weekend. Meanwhile, a low-pressure wave is gradually developing over the northern Plains. As the main trough ejects eastward near the U.S.-Canadian border Sunday into Monday, expect a round of strong thunderstorms to sweep from west to east across the northern Plains later on Sunday, reaching the upper Midwest overnight Sunday or early Monday. Otherwise, expect some showers and a few embedded thunderstorms across the Great Lakes to northern New England as a reinforcing cold front dips into the region through this weekend. Kong 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 $$