Train of three storms to spread a swath of snow
Jan 16, 2013 at 10:17 PM
AccuWeather reports the caboose in a train of storms is forecast to swing northward at the last minute, spreading a swath of snow to some coastal areas in the mid-Atlantic and New England before the end of the week.
The strongest of three storms in the train will swing up from the South just enough to spread heavy snow from the southern Appalachians to central North Carolina and a large part of Virginia later Thursday into Thursday evening.
For part of this region, this will be the first significant accumulation of snow of the season.
A rather sharp northwestern edge of the accumulating snow is likely in the mid-Atlantic and New England.
A matter of a couple of dozen-mile fluctuations in that northwestern edge may determine whether or not certain areas along I-95 receive enough snow to cause travel problems.
It will be a delicate balance between fresh, cold, dry air arriving and moisture being thrown northward from the storm and high pressure over the Atlantic Ocean.
The storm will bring a change to heavy snow from southwest to northeast over part of the interior South Thursday into Thursday evening.
During Thursday night, snow will fall over much of the Delmarva Peninsula, with the Washington, D.C./Baltimore metro areas likely winding up on the northwestern edge.
The swath from Roanoke and Richmond, Va., to Dover, Del., and Atlantic City, N.J., are forecast to be in the heart of the heavy snowfall as well as the southern end of the Shenandoah Valley in Virginia.
With such a dynamic storm system, there is a possibility of thunder with the snow.
Several inches of snow are possible on eastern Long Island, Cape Cod and the islands. Providence, R.I., is currently on the northwestern edge for a few inches of snow versus or little no accumulation late Thursday night into Friday morning.
As AccuWeather.com meteorologists see it now, the heaviest accumulating snow is likely to stay south and east of Philadelphia, the five boroughs of New York City and south of Boston. Odds favor this storm swinging south and east of much of New Hampshire and Maine.
However, a shift in storm track of 50 to 100 miles would make the difference between heavy, accumulating snow or not in these cities and others. There is also a remote chance that the high pressure area off the Atlantic Coast remains so strong that it drives the snow much farther north in the Northeast and forces rain to extend farther up the coast and inland over Virginia.
Since the storm is occurring mostly during the nighttime hours Thursday to the first part of the day Friday, the snow will fall at a time when road surface temperatures are cooling.
As a result, snow and slush can accumulate on many road surfaces in the heavy snow area, even despite the warmth of recent days.
Expect slippery travel in areas where anything greater than in inch of snow is forecast.
NOTE: This story was written by Alex Sosnowski, expert senior meteorologist for AccuWeather.com.