Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 427 AM EDT Wed Mar 29 2017 Valid 12Z Wed Mar 29 2017 - 12Z Fri Mar 31 2017 ...There is as slight risk of severe thunderstorms over the Middle/Lower Mississippi Valleys... ...Heavy snow likely for the Cascades and the Northern Rockies/Great Basin... ...Heavy rain possible over parts of the Pacific Northwest and the Lower/Middle Mississippi Valley... Low pressure over the Southern Plains will slowly move northeastward to the Middle Mississippi Valley/Western Ohio Valley by Thursday evening. The storm will produce showers and thunderstorms over parts of the Central/Southern Plains and Middle Mississippi Valley into parts of the Southern High Plains that will move eastward to the Ohio Valley/Tennessee Valley and Central Gulf Coast by Thursday evening. Showers and thunderstorms will also develop over parts of the Central/Southern Appalachians and the Southeast on Thursday afternoon into Thursday evening. In addition, rain will develop over parts of the Middle Missouri Valley on Wednesday morning and expand into parts of the Upper Great Lakes by Wednesday evening. By Thursday rain will move into the Great Lakes and into parts of the Northern Appalachians by Thursday evening. Additionally, rain and higher elevation snow will develop over parts of the Central/Southern Rockies ending by Wednesday night. Snow will also develop over parts of the Upper Great Lakes overnight Wednesday into Thursday evening. Meanwhile, upper-level energy over the Eastern Pacific will move onshore over the West Coast by early Thursday morning forming an upper-level low over the Great Basin by Thursday evening. A plume of moisture will stream into the Pacific Northwest on Wednesday that will slowly move southward along the coast to Southern California by Thursday morning while weakening. Rain and highest elevation snow will develop over the Pacific Northwest into parts of the Northern Rockies on Wednesday. Overnight Wednesday as the upper-level energy moves onshore, the snow levels over the Northwest will lower. By Thursday morning, rain and higher elevation snow will move into parts of Northern California/Great Basin and Central Rockies through Thursday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php