Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 347 PM EDT Wed May 22 2019 Valid 00Z Thu May 23 2019 - 00Z Sat May 25 2019 ...Severe thunderstorms and flash flooding likely across the Central Plains and Middle Mississippi Valley this evening... ...Cool temperatures remain across the Southwest as heat builds into the Southeast to end the week... An active weather pattern continues across much of the U.S. to end the week. The current low pressure system over the Upper Midwest Wednesday afternoon is forecast to lift northward towards Canada by Thursday, with an associated cold front extending back into the Central Plains. Thunderstorms are forecast to form along this boundary later this afternoon, with a few storms likely turning severe. The Storm Prediction Center has issued a moderate risk for severe thunderstorms across northeast Oklahoma, southeast Kansas, into portions of southwestern Missouri. These areas have also seen an abundant amount of rain over the last few days. Therefore, there is also a moderate risk for flash flooding across this region. By Thursday, the low pressure system will swing southeastward from Canada and across the Northeast Thursday night. This will bring scattered rain and thunderstorms across the Mid-Atlantic and New England. A few thunderstorms could turn severe across Pennsylvania and northern Maryland. The chance of strong thunderstorms and heavy rainfall will increase once again across the waterlogged Central Plains Thursday and Friday. The reason for yet another round of heavy rain will be a low pressure system that is forecast to emerge from the Central Rockies on Friday. Thunderstorms will form along the quasi-stationary front set up across the Central Plains and ahead of the dry-line situated in west Texas. The Southwest will remain cool and dreary through Friday with widespread light to moderate precipitation expected to continue. The Sierra Nevada and the higher elevations of the central to northern Rockies will likely have additional accumulating snow. High temperatures will remain 10 to 20 degrees below normal for this time of year. The opposite weather pattern will be the case across the eastern half of the nation. An upper-level ridge and a strong surface high will keep anomalous heat centered over the Southeast states over the next couple of days and beyond. Widespread highs in the 90s are expected for much of the Deep South and extending eastward to the Carolinas, with heat indices approaching the triple digits in a few spots. After a couple days of pleasant temperatures across the Mid-Atlantic region midweek, a return to more summer-like conditions is expected for the end of the week. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php