Accuweather just issued this forecast for the nation:
East Facing Major Post-Christmas Winter Storm
State College, Pa. — 25 December 2012 — AccuWeather reports after slamming the southern Plains and Deep South on Christmas Day, a powerful winter storm will take aim on the East and central Great Lakes on Wednesday into Thursday.
The post-Christmas storm will be far more potent than the system guaranteeing a white Christmas for more of the Northeast.
The storm, which is currently moving through the Rockies, will instead be complete with substantial snow, an icy mix, soaking rain, strong winds and severe weather.
Snow Totals to Top a Foot
On the storm’s cold northern and western flank, substantial snow will spread from the lower Ohio Valley to the eastern Great Lakes and interior Northeast on Wednesday into Thursday.
More than a foot of snow will bury places from extreme northwestern Pennsylvania to northern Maine and neighboring communities in Canada’s St. Lawrence Valley.
Between 6 to 12 inches is expected over surrounding areas, including Portland, Maine, and back to Detroit, Mich., and Indianapolis, Ind.
A half of a foot or more of snow will alone clog roads and severely disrupt travel and daily routines, but gusty winds will worsen the situation by blowing and drifting the snow around.
Soaking Rain to Bring Flash Flood Threat
Severe weather is not the only concern on the storm’s warm side, but also torrential rain capable of causing urban and flash flooding.
Soaking rain will develop late tonight across eastern Texas and the lower Mississippi Valley.
The rain will then spread northeastward to the central and southern Appalachians through Christmas night, before invading more of the Carolinas, mid-Atlantic and southern New England on Wednesday into Thursday morning.
For many in the Deep South, the soaking will precede the Christmas Day outbreak of damaging thunderstorms and tornadoes.
Farther to the north, the heaviest rain and accompanying flash flood threat will reach Charlotte, N.C., on Wednesday, Washington, D.C., and Baltimore on Wednesday afternoon, Philadelphia and New York City on Wednesday night and Boston late Wednesday night into Thursday morning.
Icy, Wintry Mix Another Concern
This potent winter storm is expected to unleash nothing but snow from Missouri to northern New England, while plain rain soaks the mid-Atlantic coast. In between, the snow will either mix with or the rain will start as a wintry mix.
The rain will mix with snow or sleet at its onset southward to the Interstate 81 corridor of Virginia, and all along the Interstate 95 corridor from Washington, D.C., to Boston. The same can be said for the Ohio Valley.
Accumulating snow will eventually mix with or change to the wintry mix in the central Appalachian Mountains and from central Pennsylvania to central New England.
Just because heavy snow is not falling, motorists should not take the wintry mix lightly. With sleet (ice pellets) involved, roads could still turn slick for a time.
Coastal Flooding/Damaging Winds Along Northeast Coast
As the heaviest rain invades the Northeast, strong winds will develop along the mid-Atlantic coast on Wednesday afternoon.
The burst of strong winds will then push northward along the coast into Thursday, whipping through Long Island and New York City on Wednesday night and Boston on Thursday morning.
The strongest winds will gust to around 50 mph for a time, threatening to cause tree damage and power outages. The combination of the winds and higher astronomical tides could also lead to coastal flooding.
Conditions throughout the East Coast will improve on Friday, when a new storm may be gathering in the Deep South.
By Kristina Pydynowski, Senior Meteorologist for AccuWeather.com