Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Sat Aug 09 2025 Valid 12Z Sat Aug 09 2025 - 12Z Mon Aug 11 2025 ...Numerous nocturnal thunderstorms are forecast to raise flash flooding threat to moderate levels across portions of the Midwest for the remainder of the weekend into Monday... An unusually robust upper-level trough for August is pushing a vigorous cold front into the upper Midwest early this morning with clusters of strong to severe thunderstorms containing very heavy rain. As the main low pressure system moves slowly east across southern Canada, the cold front trailing from the system will gradually stall across the Midwest into the central Plains through the next couple of days. Rounds of strong to severe thunderstorms are forecast to repeatedly develop and impact portions of the Midwest into the central Plains especially during the night-time hours. Hourly rain amounts to 2.5" along with multi-day rain totals locally to 9" can be expected along a corridor from northern Missouri across southern Iowa and into southern Wisconsin. Given antecedent heavy rainfall during recent weeks, numerous flash floods, some with significant impacts, are expected in this area. Meanwhile, heat and humidity will remain ahead of the aforementioned stalling front, in contrast with much cooler air behind the front from the northern Rockies to the northern Plains and down into the central High Plains through the next couple of days. Some Canadian wildfire smoke will also accompany the cool air. The amplifying upper trough across the Rockies will lead to dry and breezy conditions, prompting elevated fire weather concerns across the Four Corners region. For the Southeast U.S., a lingering frontal boundary near or just off the coast interacting with cyclonic disturbances within a tropical wave will keep enough low level moisture and instability in place to fuel the development of scattered showers and storms. The greatest chance for these storms to develop and linger will be from northern Florida/southern Georgia westward along and near the northeast and north-central Gulf coast, bringing a limited and localized risk of excessive rainfall through the weekend and into Monday. Heat continues across the Desert Southwest, but with lesser intensity this weekend into Monday, compared to recent days. High temperatures across Arizona and eastern California deserts should still approach, if not slightly exceed, 110F. Across the Great Lakes and New England, a gradual warming trend will bring temperatures well into the 80s and lower 90s through the next couple of days and into early next week. The Southeast should remain somewhat cooler than average due to the expected rainfall and cloudiness. Kong/Roth Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php