Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 PM EDT Sun Apr 19 2015 Valid 00Z Mon Apr 20 2015 - 00Z Wed Apr 22 2015 ...There is a slight risk of severe thunderstorms for parts of the Southern Plains eastward to the Southeast... ...Heavy rain possible from parts of the Northern Mid-Atlantic... Upper-level energy over the Southern Plains will merge with another area of upper-level energy over the Upper Mississippi Valley to form a closed upper-level low over the Upper Great Lakes by Tuesday. The storm will produce showers and thunderstorms over the Southeast that will move northward to Southern New England by Tuesday morning. A second area of showers and thunderstorms will develop over the Lower/Middle Mississippi Valley and move eastward to the Mid-Atlantic/Southeast by Monday evening before moving off the East Coast by Tuesday. In addition, rain will develop over parts of the Upper Mississippi Valley/Great Lakes into parts of the Northern Mid-Atlantic by Sunday evening that will move eastward to the Northeast by Tuesday morning. Light rain will linger over parts of the Lower Great Lakes on Tuesday while snow will develop over parts of the Upper Great Lakes/Upper Mississippi Valley. Elsewhere, weak upper-level energy will aid in producing scattered areas of light snow over parts of the Central Rockies on Sunday evening into Monday morning. On Monday, weak moisture will surge northward from the Gulf of Mexico over the Southern/Central High Plains that will aid in the development of an area of snow and lower elevation rain over parts of the Central Rockies that will move southeastward to the Southern Plains becoming an area of rain by Tuesday morning. Additionally, moisture coming off the Western Gulf of Mexico will aid in producing showers and thunderstorms over parts of the Lower Rio Grande Valley early Monday into Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php