Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 509 PM EDT Fri Sep 26 2025 Valid 00Z Sat Sep 27 2025 - 00Z Mon Sep 29 2025 ...Waves of low pressure moving along a nearly stationary frontal boundary will bring numerous showers and thunderstorms to much of the Southeast for the weekend... ...Southerly fetch of moisture around a slow-moving upper-level low to bring rounds of showers and thunderstorms with a threat of flash flooding to parts of the Southwest the next few days... ...All eyes will be on Potential Tropical Cyclone 9 as it approaches the Southeast Coastline early next week... Gulf moisture will pool along a frontal boundary that is forecast to slow down and become nearly stationary across the southern Mid-Atlantic and the Southeast over the weekend, resulting in a couple days of unsettled weather with several rounds of showers and thunderstorms likely. Additionally, atmospheric lift from an upper low, combined with diurnal heating and relatively high precipitable water, will present the threat of repeating clusters of heavy rain that may bring localized flash flooding potential. The greatest chance for seeing flash flooding will be on Saturday from South Carolina to the Virginia Tidewater. WPC has a Slight Risk for Excessive Rainfall to cover this potential. Showers and thunderstorms will likely persist for Sunday in the Southeast, but the dynamics for flash flooding looks less favorable than Saturday, so a Marginal Risk for Excessive Rainfall will be in place. The soil saturation will be important to monitor ahead of Potential T.C. Nine as it approaches early next week. Heading out west, an upper-level low will cutoff and spin over southern California and southwest Arizona the next few days. As the cutoff low sits and spins, it will continuously draw a fetch of enhanced moisture northward into the Southwest U.S., setting the stage for daily chances for widespread showers and thunderstorms. Heavy rainfall rates are likely to occur with this activity, increasing the risk for excessive rainfall and flash flooding over sensitive terrain like burn scars, slot canyons, etc... A Slight Risk for Excessive Rainfall is in effect on Saturday for the deserts of southeast California to western Arizona, as well as much of New Mexico as moisture creeps eastward with the upper low. Then, the Slight Risk for Excessive Rainfall will remain present over New Mexico on Sunday as impressive moisture surges northward ahead of the upper low. The threat of lightning will accompany these storms, so any recreational activities in the Southwest for the weekend will need to be planned carefully. Potential T.C. Nine located near the Bahamas will likely present the risks of heavy rainfall and flash flooding, gusty winds, and coastal flooding to the Southeast coastline early next week. There is a lot of uncertainty with the forming storm, but folks in the Southeast should get their hurricane plans ready and listen to local officials. For the official forecast, follow the National Hurricane Center at nhc.noaa.gov. Elsewhere across the country, the Plains and Mississippi Valley should remain mainly dry as high pressure will more or less dominate. A weak cold front will sweep through the Midwest and Great Lakes, but temperatures will not cool off much behind it. The ridge of high pressure will build in behind the front, and temperatures will warm up to as much as 10-15 degrees above average across the northern U.S.. High temperatures in the middle 80s will be likely for much of the northern tier. Temperatures may approach 90 by Sunday. In stark contrast, for places in the Southeast and Southwest that are cloudier and stormier, high temperatures will generally be 5 to 10 degrees below normal. Wilder/Miller Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php