Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 209 PM EST Sun Jan 20 2019 Valid 00Z Mon Jan 21 2019 - 00Z Wed Jan 23 2019 ...Major winter storm will begin to wind down over the Northeast... ...Heavy snow possible over parts of Northern Maine, Sierras, Great Basin, and Northern/Central Rockies... ...Temperatures will be 10 to 20 degrees below average over parts of the Great Lakes, Ohio Valley, and into parts of the Northeast/Mid-Atlantic... A major winter storm will slowly wind down as the storm over the Gulf of Maine moves northeastward into the Canadian Maritimes by Monday morning. The heavy snow over Northern Maine will end overnight Sunday. In the wake of the storm, lake effect snow will develop downwind from the Great Lakes and upslope flow will aid in developing snow over parts of the Central Appalachians through Monday evening. The lake effect snow will end, west to east, Monday into Monday evening. Meanwhile, a storm moving onshore over the West Coast will move eastward to the Central Plains by Tuesday. The system will produce rain and higher elevation snow over parts of the Pacific Northwest/Northern California and snow over parts of the Northern Rockies. Overnight Sunday, snow will move into the Sierras and parts of the Great Basin as snow develops over parts of the Northern Plains. Snow will develop over parts of the Central Rockies on Monday. The rain and snow will end over California/Nevada and the Pacific Northwest by Monday night. The snow over the Northern Plains will expand into parts of the Upper Mississippi Valley by Monday evening, too. Snow will also move into parts of the Upper Great Lakes overnight Monday. On Tuesday, rain will develop over parts of the Lower/Middle Mississippi Valley and parts of the Central/Southern Plains. In addition, onshore flow will develop over the Pacific Northwest late Monday night into Tuesday. The moisture will aid in producing rain and higher elevation snow over parts of the Pacific Northwest early Tuesday morning into Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php