Impacts from a storm targeting millions of people in the eastern states will range from travel disruptions caused by heavy snow to power outages produced by strong winds to flooding from storm surge.
A major storm will bring heavy snow from parts of North Carolina to portions of West Virginia, Pennsylvania and New Jersey spanning Wednesday into Thursday.
The storm will be moving through the central Appalachians toward the mid-Atlantic coast during the middle of the week, after blasting portions of the Plains and Midwest Monday into Tuesday.
Based on the latest information, the area that is most likely to receive a foot or more of snow lies from northwestern North Carolina through northern and western Virginia, the mountains of West Virginia and western and part of central Maryland.
Charlottesville, Roanoke, Harrisonburg and Winchester, Va.; Frederick and Hagerstown, Md. and Martinsburg, W.Va. appear to be in the middle of the zone with the greatest snow potential. This potential would be immobilizing snow. The weight of heavyweight snow can bring down trees and power lines in this area.
However, dozens of other cities in the region could receive anywhere from a couple of inches of slush to a foot or more of back-breaking snow. These include Washington, D.C., Baltimore, Md., Richmond, Va., Dover, Del. and Vineland, N.J. These areas are likely to receive rain during part of the storm and a larger percentage of the snow that falls is more likely to melt for a time.
As the rate of snow becomes heavy, roads can quickly become clogged with snow, potentially stranding motorists. Deicing time will increase at area airports in the path of the storm. Potential flight delays and cancellations from heavy snow will hit Minneapolis and Chicago first, then will spread to multiple airports in the I-95 mid-Atlantic with the possibility of delayed aircraft and crews elsewhere across the nation.
There is still the risk the storm strengthens upon nearing the coast and either turns farther to the north or grows in size spreading snow and other effects farther north.
Philadelphia, Pittsburgh and Harrisburg are also on the bubble with the chance of a period of heavier snow that can bring a big accumulation or lesser snow to primarily a rain/snow mix. These details will not be known until the storm is virtually under way. A shift in track of the storm and its heavy snow by 50 miles can make the difference.
New York City is likely to be on the northernmost edge of the lesser snow area. Unless the storm stalls and expands substantially northward, a heavy snowfall appears to be a low probability. Cape Cod and Long Island, which extend out into the Atlantic a bit more, have a slightly higher chance of a period of accumulating snow.
A slightly more southerly track would throw heavier snow farther south over western and central North Carolina. As a result folks in Charlotte, Winston-Salem and Raleigh, N.C. and Norfolk, Va. should watch this storm closely.
Wind, Coastal Flooding and Beach Erosion
Based on the latest information, AccuWeather.com meteorologists feel this storm will deliver the punch of a moderate to strong nor'easter. Such storms produce winds over a large fetch of water and drive that water toward the coast. The shape of the coast and wind direction determines which areas are most susceptible to coastal flooding. The duration and strength of the onshore wind determines the severity of the water rise.
Winds can become strong enough to cause sporadic power outages from eastern North Carolina to southern New Jersey. Gusts to 60 mph are possible. A 24 to 48 hour period of pounding surf will cause moderate beach erosion in these areas. Offshore seas can reach 30 feet.
Areas from eastern North Carolina to southern New Jersey are most likely to have coastal flooding problems during times of high tide Wednesday into Thursday. While it is a bit too early to be highly confident on water level rises, there is a chance of tides levels running between 2 to 4 feet above published values. Fortunately, astronomical impact around the time of the storm is minimal with significant distance between the new and full moon phases.
Because of the track and speed as to which the storm will strengthen, the risk of coastal flooding problems over portions of the Chesapeake and Delaware Bays cannot be eliminated at this time. There may be a period where winds are from a direction to cause water to back up.
EDITOR'S NOTE: This story was written by Alex Sosnowski, expert senior meteorologist.