A major winter weather event will develop over the Western U.S. during the next couple of days as a strengthening trough of low pressure drops down the West Coast.
A blast of cold air from the north and a surge of moist onshore flow from the Pacific will accompany the system during it's southward progression. This combination of weather factors will translate into moderate to heavy snow totals from the Pacific Northwest through the Northern High Plains. Coastal and lowland areas of the Pacific Northwest may see snow accumulations of 1 to 2 inches, while 4 to 8 inches develop farther inland and across areas of the Northern Intermountain West. The heaviest snow totals are expected in the Northern Rockies with 8 to 12 inches, and in the northern Blue Canyon Mountains with 1 to 2 feet. In addition to snow, strong winds will sweep across the region, creating periods of blowing and drifting snow, reduced visibilities and hazardous travel conditions.
East of the Rockies, a very active weather day is expected across the middle of the nation. An energetic wave of low pressure from the west will meet with warm, moist air streaming up from the south and cold air surging in from the north over the Southern Plains, Lower to Mid-Mississippi Valleys and the Tennessee Valley. Conditions will be favorable for thunderstorms, heavy rain and severe weather activity with damaging winds and possible tornadoes from eastern Texas through the Ozarks and into the Tennessee Valley. Snow and ice will also be possible with this storm in the Central Plains. Wet weather is expected to reach the Appalachians by Thursday evening and the Mid-Atlantic and southern New England areas by Friday.
Temperatures in the Lower 48 states Wednesday ranged from a morning low of -20 degrees at Saranac Lake, N.Y., to a high of 89 degrees at Falfurrias, Texas.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov