Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 459 PM EDT Sun Apr 16 2017 Valid 00Z Mon Apr 17 2017 - 00Z Wed Apr 19 2017 ...There is a slight risk of severe thunderstorms over parts of Southern Plains... ...Heavy snow possible for parts of the Sierras... A front extending from the Northeast to the Southern High Plains will move off the Northeast/Mid-Atlantic Coast by Monday evening while the second part of the boundary extends westward from the Southern Mid-Atlantic to the Central Plains by Tuesday. Showers and thunderstorms will develop along and ahead of the front from parts of New England to the Central/Southern Plains by Sunday evening. Overnight Sunday, the showers and thunderstorms over Northeast and Northern Mid-Atlantic will move off the coast. Showers and thunderstorms will continue over the Southern Mid-Atlantic to parts of the Southern Plains/Lower Mississippi Valley through Tuesday. Light rain will also develop over parts of the Northeast and Lower Great Lakes on Monday into Tuesday. Some snow will develop over Northern Maine Monday evening into Tuesday, too. A second front moving onshore over the Pacific Northwest on Sunday evening will move inland to parts of the Upper Mississippi Valley to the Central Plains and into parts of the Great Basin by Tuesday. The system will produce rain over parts of the Pacific Northwest and California Coast on Sunday evening that will expand eastward to parts of the Northern Rockies and segments of the Great Basin. Overnight Sunday, snow will also develop over some of the higher elevations of Pacific Northwest and the Northern Rockies. The rain will continue to expand eastward into the Northern High Plains by Monday evening. As the associated upper-level trough moves inland, snow levels over California will lower as snow develops over the highest elevations of the Sierras Monday into Tuesday. As the West Coast system moves onto the Northern Plains, showers and thunderstorms will develop over parts of the Northern Plains into parts of the Central Plains overnight Monday moving into parts of the Upper Mississippi Valley/Upper Great Lakes by Tuesday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php