Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 321 AM EST Fri Dec 25 2020 Valid 12Z Fri Dec 25 2020 - 12Z Sun Dec 27 2020 ...There is a Moderate Risk of excessive rainfall over parts of Northern New England... ...Heavy lake effect snow downwind from the Great Lakes; heavy areas of snow over parts of the Cascades, Sierra Nevada, and the Northern Rockies... A strong front moving off the East Coast, having an intense connection to moisture from the Atlantic, will produce heavy rain over parts of the Northeast on Christmas. The WPC has issued a Moderate Risk of excessive rainfall over parts of Northern New England. The heavy rain will help produce numerous areas of flash flooding, with some significant areas of flash flooding possible. Furthermore, many streams may flood, potentially affecting larger rivers. The rain will change over to snow over parts of the Northern Mid-Atlantic on Christmas before ending later Christmas evening. The rain will also change over to snow over the Northeast by Saturday morning. Snow will linger over parts of the Central Appalachians into Saturday morning. Additionally in the wake of the storm, upper-level energy and cold air flowing over the Great Lakes will help produce lake effect snow downwind from the Great Lakes. Snow amounts will be much heavier downwind from the Lakes Erie and Ontario ranging from 12 inches to 18 inches before the snow ends on Sunday. The snow will contribute to hazardous driving conditions. Meanwhile, a front moving onshore over the Pacific Northwest will move inland to the Northern Intermountain Region before dissipating on Saturday. The system will produce coastal rain and higher elevation snow over the Pacific Northwest and Northern California on Christmas. Overnight Christmas, the snow will move into parts of the Northern Intermountain Region and into parts of the Sierra Nevada and Northern Rockies on Saturday. Overnight Saturday, the rain will taper off over the Northwest, with the snow beginning to taper off over the Northern Intermountain Region/Northern Rockies. The snow will contribute to hazardous driving conditions. Elsewhere, the SPC has issued an elevated risk of fire weather over parts of the Southern High Plains/Southern Plains through Saturday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php