A low pressure system over the Southeast converges with a trough over the Mid-Mississippi Valley to produce periods of heavy rain in the South and snow in the North. The system will quickly move northeastward up the East Coast into New England. Flow around this system pulls moisture in from the Atlantic Ocean and allows for rain and snow showers to develop from the Central Appalachians to Maine. Total snowfall accumulation will range from 1 to 3 inches, with locally higher amounts at higher elevations. Some parts of Maine may see up to 6 inches Tuesday. The western side of this system will pull cool and dry air over the Great Lakes, which will kick up lake effect snow showers over the eastern shores. Expect 2 to 4 inches of heavy and wet snow over western New York, and 1 to 2 inches across western Michigan.
Farther west, high pressure builds over the Plains and Mississippi River Valley and pushes bitterly cold air into the Central U.S. The Northern Plains and Upper Midwest will see daytime highs in the single digits, while overnight lows will remain below zero, with windchills between 30 and 40 degrees below zero. High temperatures will only reach into the 30s and 40s as far south as northern Texas and Oklahoma.
Expect more snow in the Rockies as a low pressure system in the Pacific Northwest and Northern Plains tracks southeastward over the Central Rockies and Southern Rockies. This system will obtain moisture from the Gulf of Mexico, and create periods of heavy snow across high elevations of Colorado and northern New Mexico. Expect 4 to 8 inches of new snow across western Colorado, up to 4 inches at higher elevations of northern New Mexico, and a dusting of snow showers across Utah.
Temperatures in the Lower 48 states Monday ranged from a morning low of -14 degrees at Crookston, Minn., to a high of 87 degrees at Melbourne, Fla.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov