Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 256 PM EST Sun Dec 16 2018 Valid 00Z Mon Dec 17 2018 - 00Z Wed Dec 19 2018 ...Heavy snow possible over the Northern Cascades and Northern Intermountain Region... ...Heavy snow and rain/freezing rain over parts of New England... ...Heavy rain possible over the Pacific Northwest Coast... A storm along the Northern Mid-Atlantic Coast will move northeastward to the Canadian Maritimes by Tuesday. The system will produce rain and snow with pockets of rain/freezing rain over parts of the Northeast. Rain will also develop over parts of the Northern Mid-Atlantic into parts of the Central Appalachians that will move off the coast overnight Sunday. Rain will end over Southern New England by Monday afternoon. Snow will continue over Northern New England through Monday afternoon, too. Upper-level energy just north of Lake Superior will move southeastward off the Northeast Coast Monday evening into Tuesday. The energy will trigger snow over the Lower Great Lakes into the Northeast on Monday afternoon that will wane over the area on Tuesday. Meanwhile, a front over the West Coast will move inland to the Northern Plains by Tuesday while another front will come onshore on Tuesday morning. Onshore flow associated with the system will aid in producing rain over the Pacific Northwest and Northern/Central California with snow over the Cascades and Blue Mountains. Overnight Sunday, the rain and higher elevation snow will expand eastward into parts of the Northern Intermountain Region and parts of the Great Basin. By Monday evening, snow and lower elevation rain will move into the Northern Intermountain Region/Northern Rockies and Great Basin. Also by Monday evening the rain will be limited to the Pacific Northwest Coast. Overnight Monday additional moisture will move onshore over the Pacific Northwest and continue into Tuesday. Rain and higher elevation snow will expand farther inland over the Pacific Northwest and into the Northern Intermountain Region by Tuesday. In addition, the snow and lower elevation rain will end over the Northern Rockies and Great Basin by Tuesday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php