Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EST Sat Dec 19 2020 Valid 12Z Sat Dec 19 2020 - 12Z Mon Dec 21 2020 ...Heavy rain in lower elevations and snow in higher elevations continue across the Northwest... ...Rain and thunderstorms spread across the south-central and southeastern U.S. while light snow spreads across the north-central U.S. and Northeast... Active weather is expected to continue across the Northwest as one frontal system exits this morning and another front approaches tonight. Higher than normal moisture amounts from the Pacific Ocean will stream into the Pacific Northwest through early next week, causing potentially heavy rain of multiple inches there. This has prompted Flood Watches and Slight Risks of excessive rainfall for the region in lower elevations. Urban and small stream flooding is possible and there is potential for landslides and debris flows in some areas. Meanwhile, despite relatively high snow levels, snow is likely at higher elevations of the Cascades of Washington and toward the Northern Rockies. Snow amounts through Monday morning are likely to be over a foot in the Cascades, with 6 to 12 inches in the Northern Rockies, Sawtooth Mountains/Bitterroots, and the Wind River Mountains/Tetons. Additionally, with strong westerly flow, high winds are a threat across the Northern Rockies toward northern and central portions of the High Plains this weekend. Farther south, an Elevated Risk of fire weather is in place for southern California where low relative humidity exists. A cold front is forecast to move eastward across the central U.S. today and give way to a front forming just offshore of the Eastern Seaboard Sunday. Precipitation should move west to east across much of the central and eastern U.S. over the weekend associated with these fronts and as Gulf of Mexico moisture streams in. Rain is expected in the Middle/Lower Mississippi Valley, Tennessee Valley, Lower Ohio Valley, and Southeast. Some thunderstorms are possible across Texas and Louisiana, and rain totals there could be over an inch today. To the north over the Upper Midwest, Great Lakes region, interior Northeast, and in higher elevations of the Appalachians, light snow or mixed precipitation is forecast. Snow amounts should be generally a couple of inches or less. Chilly temperatures remain in the East today underneath a cold high pressure system, and parts of the Northeast will wake up to single digit lows this morning given the snowpack. Temperatures should moderate somewhat on Sunday. Meanwhile, milder than normal temperatures are forecast for the north-central U.S., with temperatures around 10 to as much as 25 degrees above normal. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php