Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 256 PM EST Fri Jan 06 2017 Valid 00Z Sat Jan 07 2017 - 00Z Mon Jan 09 2017 ...Winter storm expected to bring potentially heavy snow from portions of the Southeast to the southern Mid-Atlantic... ...Heavy rain and mountain snow expected for central and northern California... ...Snow and ice accumulations possible for portions of the Pacific Northwest and Intermountain West... A developing low pressure system in the northern Gulf of Mexico is expected to bring a potentially significant winter storm to parts of the Southeast and southern Mid-Atlantic tonight and tomorrow. Cold air in place over the region will allow for snow on the northern edge of the precipitation shield from northern Mississippi to the Mid-Atlantic. The low strengthens as it moves northward just off the Southeast coastline, which will allow for significant accumulations across central North Carolina and southeast Virginia where as much as 6 to 12 inches of snow, with locally higher amounts, is forecast. Light to moderate accumulations of sleet or freezing rain is also possible in the transition zone between rain and snow across portions of the Southeast. Light to moderate snow may also clip eastern portions of the Northeast as the low moves away from the coast on Saturday. High pressure moves in behind this system which keeps the cold air around through the weekend, with afternoon high temperatures 10 to 20 degrees below normal. After a break today, expect wet weather to once again move into the Western U.S. this weekend. Widespread heavy rain is likely all weekend across northern and central California, with several inches of rain, or more, expected. Repeated rounds of heavy rain will bring a flash flood threat to the region as well. Inland, expect heavy snow in the mountains with feet of snow possible in the highest elevations of the Sierras. Farther north, cold air locked in place across the Northwest will bring the potential for snow and ice accumulations across western Washington and Oregon. Rain and snow will also spread eastward into the Intermountain West and the Rockies with heavy snow possible in the highest elevations. By Sunday, warmer air moves in, which should change precipitation for coastal areas to mostly rain, but freezing rain may continue for interior valleys of Oregon and Washington, as well as into the Great Basin. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php