Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 AM EST Sat Dec 31 2016 Valid 12Z Sat Dec 31 2016 - 12Z Mon Jan 02 2017 ...Heavy rain possible over parts of the Central/Eastern Gulf Coast ... ...Snow for parts of the Upper Mississippi Valley to the Northeast... ...Snow possible for the hills of Southern California... ...Snow levels will be down to the coast over parts of the Pacific Northwest... A front extending from the Great Lakes to the Southern Plains will advance eastward off the Northeast/Mid-Atlantic Coast and southward to interior Gulf Coast States by evening on New Year's Day. The system will produce snow over the Great Lakes on Saturday morning that will move to the Northeast overnight New Year's Eve and off the coast by evening on New Year's Day. Rain will develop ahead of the boundary over the Western Gulf Coast/Lower Mississippi Valley that will extend from the Ohio Valley to the Central Gulf Coast by Saturday evening. The rain will end over the Ohio Valley by New Year's Day. The rain will continue over the Central Gulf Coast to parts of the Southeast Coast by Sunday evening. Southerly flow ahead of a cold front dropping southward through the Plains will tap into Gulf of Mexico moisture bringing widespread rain to much of the Deep South beginning on Saturday. The heaviest and most organized of the rainfall is expected along a frontal boundary draped across the central Gulf Coast. WPC has highlighted a marginal to slight risk for excessive rains/flash flooding from the lower Mississippi Valley to the Southeast. Rain also continues on Sunday, spreading into the Mid-Atlantic as the northerly cold front becomes stationary across the Mid-Atlantic, Tennessee Valley, and lower/middle Mississippi Valley. On the north side of this system, snow will be possible near the surface low as it tracks from the Upper Midwest to New England this weekend. Mainly light accumulations in the 2 to 4 inch range are expected, except downwind of the lakes where snow amounts may be enhanced due to lake effect. Rain and mountain snow is likely across the Southwest, Four Corners, and southern Rockies as a series of upper level systems moves through this weekend. To the north, behind a cold front dropping through the mountains, cold air is in place, with afternoon high temperatures on Saturday expected to be 10 to 20 degrees below normal across much of the Western states. A second front, with a reinforcing shot of cold air, moves into the Pacific Northwest on Saturday, pushing quickly southward to the Great Basin by Sunday. Another round of coastal rain and mountain snow is expected to spread across much of the Northwest this weekend. As usual, the heaviest of the snowfall can be expected in the higher elevations of the Cascades and northern Idaho. With sufficient cold air locked in place though, even some of the lower elevations may see some snow showers. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php