Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 424 AM EDT Mon Apr 24 2017 Valid 12Z Mon Apr 24 2017 - 12Z Wed Apr 26 2017 ...Heavy rain possible over the Carolinas... ...Heavy rain possible over parts of the Pacific Northwest/Northern California... ...Snow possible for parts of the Northern/Central Rockies and the Cascades... Low pressure over the Southeast will slowly move northward to the North Carolina Coast by Tuesday evening. The system will produce showers and thunderstorms over parts of the Southeast and portions of the Southern Mid-Atlantic that will move off the Southeast Coast by Tuesday morning and remain over parts of the Southern Mid-Atlantic Coast through Tuesday evening. Rain will also develop over the Virginias that will slowly expand northward into the Northern Mid-Atlantic/Lower Great Lakes and Southern New England by Tuesday morning and continue to expand northward into Northern New England by Tuesday evening. Meanwhile, a front extending from the Northern Plains to the Central High Plains into the Great Basin will move eastward to the Upper Great Lakes/Middle Mississippi Valley to the Southern High Plains into the Southwest by Tuesday evening. The storm will produce rain and snow over parts of the Northern Plains into the Upper Great Lakes that will move into parts of Upper/Middle Mississippi Valley and Northern Plains by Monday evening. As the system moves eastward, moisture will move northward from the Western Gulf of Mexico and pool along the boundary. Overnight Monday, the rain and snow will change over to all rain over parts of the Upper Mississippi Valley/Upper Great Lakes through Tuesday. In addition, showers and thunderstorm will start to develop near the front over the Middle Missouri Valley overnight Monday expanding into the Central Plains by Tuesday morning and continue to expand into the Central High Plains and parts of the Southern Rockies by Tuesday evening. In the meantime, upper-level energy will move onshore over the Pacific Northwest and move southeastward to the Central/Southern High Plains and the Central/Southern Plains by Tuesday evening. Some moisture will accompany the energy onshore over parts of the Northwest into Northern/Central California on Monday into Monday evening. Rain and highest elevation snow will develop over parts Pacific Northwest into Northern California through Tuesday morning. Snow and lower elevation rain will develop over parts of the Northern Rockies on Monday morning that will expand into parts of the Central Rockies/Great Basin by Monday evening and continue over the area through Tuesday evening. Additional upper-level energy will move onshore over the Pacific Northwest on Tuesday into Tuesday evening. The energy will aid in producing rain over parts of the Pacific Northwest Coast by Tuesday afternoon and expand inland by Tuesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php