Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 PM EDT Sat Apr 30 2016 Valid 00Z Sun May 01 2016 - 00Z Tue May 03 2016 ...Severe thunderstorms possible over parts of the lower/middle Mississippi Valley... ...Heavy rain possible over the lower Mississippi Valley and central Appalachians... ...Snow over parts of the Central Rockies and central High Plains ... A stable upper level pattern will lead to slow eastward progression of the large storm system affecting several regions of the nation. The cold front across the central U.S. will lurch eastward and and even become stationary for a brief time. Ahead of the front, southwesterly flow is transporting a warm and moist air mass northward from the Gulf Coast into the Ohio Valley and eventually into the Mid Atlantic. Showers and thunderstorms are expected to affect areas along and ahead of the front as it pushes across the eastern U.S. Locally heavy rainfall could lead to flash flooding across portions of the lower Mississippi Valley, eastern Ohio Valley, and the central Appalachians. Portions of the central and lower Mississippi Valley could see severe thunderstorms today. Further west, moisture wrapping back around the surface low over the central Plains will bring snow to portions of the central High Plains. As the surface low pulls off to the east the snow will taper off tomorrow morning. An upper level low driving southeastward over the Southwest today will generate rain showers and higher elevation snow. As the upper low pushes toward the southern Plains snow will overspread the central Rockies with heavy snow possible across the higher elevations. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php