The potential exists for a major snowstorm to affect more than 50 million across the eastern United States at the end of the week.
Areas from near Washington, D.C., to around New York City are within the swath most likely to receive the heaviest snow from the storm.
The exact track of a storm will hold the key as to which areas in mid-Atlantic and New England are hit with heavy snow, dangerous highway travel and scores of flight delays and cancellations during Friday into Saturday.
Unlike most storms so far this winter, this system will have sufficient enough cold air to produce snow and disruptions to daily activities in some areas of the East that have seen little thus far.
If the storm develops to its full potential and takes a track just off the mid-Atlantic and New England coasts, then a blizzard can unfold. The storm could shut down highways and perhaps cause airports to close.
This is the type of storm that is likely to produce a very heavy rate of snow.
Since the storm will strengthen rapidly and will tap plenty of moisture from the Gulf of Mexico and the Atlantic Ocean on its path, snowfall rates of 1-3 inches per hour are possible. There is the potential for the hardest-hit areas to receive 1-2 feet of snow from the storm.
In the swath of heaviest snow, motorists who venture out during the storm could become stranded.
Thunder and lightning could accompany the heavy snow in some coastal locations.
As the storm strengthens near the coast, winds will increase, and blowing and drifting snow will develop.
Along the mid-Atlantic and New England coast, a period of rough seas, minor coastal flooding and beach erosion can occur. The approaching full moon will cause high astronomical tides around the days where the storm will be near the coast, leading to heightened coastal concerns.
The storm will roll onshore in northern California to start the week, then dip southward toward the Gulf of Mexico at midweek, before turning northeastward along the Atlantic coast on Friday.
The wintry mix will ramp up over the southern Appalachians during Thursday night.
On Friday, the wintry part of storm will focus on the mid-Atlantic region.
Part of New England would be most affected by the storm from Friday night into Saturday night.
Based on the most likely storm track at this time, the swath from Washington, D.C., to Baltimore and Philadelphia appears to be smack in the middle of the swath of heavy snow.