Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 324 AM EDT Wed May 21 2025 Valid 12Z Wed May 21 2025 - 12Z Fri May 23 2025 ...Severe Weather and Flash Flooding expected over the Ohio Valley/Mid-Atlantic today... ...Above average temperatures across southern tier states and West; below average temperatures from Northern Plains to Northeast/Mid-Atlantic... Severe storms and excessive rainfall concerns should diminish considerably across the lower 48 through mid-week. A pair of low pressure systems moving through the Midwest and East Coast will continue to focus scattered to isolated showers and thunderstorms along its path. Some of today's storms could turn severe, producing large hail, strong wind gusts and a tornado or two, according to the Storm Prediction Center. SPC issued a Slight Risk (level 2/5) of Severe Thunderstorms from the Ozarks to the Mid-South and far eastern North Carolina to account for this threat. Multiple rounds of showers and thunderstorms could pose a flash flooding threat to parts of the Central Appalachians, including the Pittsburgh metro area today. Flood Watches are in effect for portions of southwestern Pennsylvania and the Maryland panhandle. An upper low, parked and spinning over the Great Lakes and Northeast, will generate cooler temperatures across the Northern Plains, Midwest, Northeast and Mid-Atlantic for the next several days. High temperatures in the 40s, 50s and low 60s will represent temperature anomalies between 20-35 degrees below average. Meanwhile, an upper ridge in the West and central U.S. will produce above average temperatures across the Southern and Western U.S.. Some high minimum temperature records may be tied or broken in Florida and southern California. Moderate to Major Heat Risk will likely increase over south Texas beneath a building upper ridge through the rest of the week. Kebede Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php