Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 254 PM EST Fri Dec 30 2016 Valid 00Z Sat Dec 31 2016 - 00Z Mon Jan 02 2017 ...Heavy to excessive rainfall possible along the central Gulf Coast with light accumulating snow across the Great Lakes... ...Rain and mountain snow possible across the Southwest, Four Corners, and southern Rockies... ...Below normal temperatures and more rain and snow moves in by Saturday across the Northwest... 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. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php