Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 AM EDT Thu May 08 2025 Valid 12Z Thu May 08 2025 - 12Z Sat May 10 2025 ...Widespread showers and storms to end the work week across much of the eastern and southern U.S.... ...Threat for scattered flash flooding Thursday for portions of the Mid-Atlantic and south Texas with a severe weather threat across the Tennessee Valley/southern Appalachians... ...Conditions remain below average across much of the eastern and southern U.S. while much above average conditions expand across the north-central and western U.S.... A broad area of showers and thunderstorms is expected today (Thursday) ahead of consolidating upper-level waves and an accompanying surface cold front from the Northeast southwest through the Ohio Valley/Southeast and westward along the Gulf Coast into southern and western Texas. Moist Gulf return flow following the dissipation of a broad area of convection overnight will provide the fuel for moderate to locally heavy rainfall and isolated flash flooding. A locally higher threat for flash flooding exists across eastern PA, northwestern NJ, and southern NY, including portions of the Poconos and Catskills. Storms will have a tendency to move parallel to the front leading to higher rain totals over already saturated soils, and a Slight Risk of Excessive Rainfall (level 2/4) in effect. Higher moisture in an airmass undisturbed by the previous days convection over south Texas will also lead to widespread storms with a locally higher threat for heavier downpours and scattered flash flooding, with a Slight Risk in effect here as well. In addition, a couple areas of severe weather are expected. First, locally stronger winds associated with one of the upper-level waves and sufficient instability with warming temperatures ahead of the cold front will lead to a cluster of strong to severe storms from the Tennessee Valley east through the southern Appalachians. The Storm Prediction Center has introduced a Slight Risk of severe weather (level 2/5) mainly for the threat of very large hail along with damaging wind gusts. Second, an upper-level shortwave passing over the Rio Grande Valley/south Texas will bring the threat for some strong to severe storms here as well, with another Slight Risk in place for additional instances of large hail and damaging winds. The front will continue eastward into Friday, with precipitation progressively ending from west to east across the Ohio Valley/southern Mid-Atlantic southwest through Texas, while storms continue ahead of the front across the northern Mid-Atlantic/New England and the Southeast. Moderate to locally heavy rainfall is again expected with some isolated flash flooding possible, particularly across central/southern New England and along the central Gulf Coast. Elsewhere, lingering moisture along the central/southern Rockies and High Plains will lead to some scattered storms Thursday and Friday. An upper-level shortwave and accompanying surface frontal system passing from the northern Rockies/High Plains Thursday to the Upper Midwest Friday will bring a chance for some isolated showers. Otherwise, much of the Midwest, Plains, and Great Basin/West Coast will be dry. The consolidating upper-trough across much of the eastern/southern U.S. while a ridge builds over the western/northern U.S. will lead to some significant variations in temperatures the next couple of days. Much of the Great Lakes/Northeast southwest through the Ohio/Middle Mississippi Valley and central/southern Plains will see below average highs under the upper-troughing. Highs in the 50s and 60s will be common for more northern locations with 60s and 70s from the Ohio Valley southwards. Conditions along the East Coast will be a bit closer to average ahead of the approaching cold front, with highs in the 60s and 70s for the Mid-Atlantic and 70s and 80s into the Southeast. In contrast, well above average temperatures will expand in coverage across the northern Plains/Upper Midwest and Interior West/West Coast. Forecast highs are generally in the 70s and 80s with 90s in the central California Valleys and low 100s into the Desert Southwest. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php