Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 133 PM EST Mon Dec 29 2014 Valid 00Z Tue Dec 30 2014 - 00Z Thu Jan 01 2015 ...An arctic high encompasses growing real estate across the Lower 48 United States, leading to light lake effect snows near the Great Lakes and upslope snows to the High Plains... ...Rare impactful snows possible across the Southwest as well... The most dominant feature on the map over the next 2.5 days is a strong arctic high oozing south and eastward across the Pacific Northwest, High Plains, and across the Mississippi and Ohio Valleys. Carrying an inherently dry air mass in tow, upslope snows into the High Plains and Front Ranges of the Rockies should be light in character. Cold air moving across the relatively warm Great Lakes around its northeast periphery should lead to some light lake effect snows across portions of Michigan, Pennsylvania, and western New York state over the next couple days. A strong packet of energy aloft diving southward into the Southwest should allow snowflakes to fall across the Southwest, potentially to the floors of the high deserts, with several inches expected within the coastal ranges east of Los Angeles and San Diego. Ahead of this system, onshore flow from the Gulf of Mexico begins to invade the Lone Star State/Texas. However, cold air is in place, so the specter of a wintry mix of precipitation haunts areas as far south as the middle Rio Grande Valley towards Del Rio. The polar front moving through the Southeast should spread showers and thunderstorms from Virginia southward into Florida with time. Where the cold air is deepest, snowfall is possible across southwest Virginia, western North Carolina, and southeast West Virginia tonight into Tuesday. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php