A nor'easter already closing schools and canceling thousands of flights Wednesday is set to bring record-setting snow to the region.
The fourth nor'easter in three weeks will dump heavy snow, winds and even coastal flooding to some areas. It has potential to be one of the most significant and most disruptive snowstorms this late in the season, CNN meteorologists said.
Snow has begun to fall and it will pick up while more than 70 million people are under a winter storm watch, warning or advisory from the southern Appalachians to Boston.
The storm will move away from the region by Thursday but not without first hitting coastal New England and Maine.
Latest developments
•More than 3,200 flights are canceled Wednesday due to storm, according to Flightaware.com.
•School closings: Public schools in New York City, Philadelphia and the District of Columbia are closed Wednesday.
Which places are affected?
New York and Philadelphia could see up to a foot of snow. The latter may get its biggest snowfall after the first day of spring in more than 100 years.
Parts of southern New England and the New Jersey coast could also see blizzard conditions if powerful winds and heavy snow bands coincide, the National Weather Service said.
The nation's capital will likely see 6 to 8 inches of snow, with some models hinting at much higher totals for the district. Areas west and north of the city are likely to see close to a foot of snow.
Track the storm with high resolution auto-updating graphics
Coastal flooding is a threat along the coast from Virginia to Massachusetts. Some of the worst coastal flooding could occur along the Jersey Shore with high tides of 2-3 feet above normal possible.
The storm already dumped 13 inches of snowfall in Greencastle, Pennsylvania and blanketed Smith Crossroads in West Virginia with 9.2 inches.
Blizzard conditions likely
With a forecast of heavy snow and winds more than 45 mph, blizzard conditions are possible.
New York City could see sustained winds of 20 to 30 mph Wednesday, and coastal areas such as Cape Cod in Massachusetts are predicted to receive gusts up to 60 mph from midmorning Wednesday to Thursday.
Storm surge will continue to pose a threat to eroding coastlines from this new coastal storm.
Coastal flooding is possible all along the coast from Virginia to Massachusetts through Thursday. Some locations along the Jersey Shore could see tides 2-3 feet above average, putting them above flood stage. This will put a strain on already vulnerable areas along the coastline, which saw dramatic storm surge from the first two nor'easters that hit over the last three weeks.
