The storm may bring major travel disruptions throughout the region.
Some areas will be at risk for flooding, while others may face power outages and property damage related to freezing rain, followed by snow and a freeze-up.
Rapid thaw and heavy rain to raise risk of flooding in coastal areas
Rounds of heavy rain and fog will be the triggers for airline and ground transportation delays from Virginia to coastal Maine.
"Two main rounds of rain are likely in the coastal Northeast," according to AccuWeather Senior Meteorologist Dave Dombek.
One round will develop near and west of the Appalachians during Thursday night and spread eastward on Friday.
The second round of rain and risk of major travel disruption is forecast to spread northeastward with the main storm from Friday night to Saturday morning.
Back toward the Appalachians, there may be a less-defined separation between the two main batches of rain.
Some motorists may encounter flooded roadways. The risk of urban flooding will not be limited to areas with existing heavy snowcover.
The thaw may be rapid enough, combined with drenching rain to lead to ice jams on some of the rivers.
"Temperatures may surge to record high levels in some areas before much colder air returns," according to AccuWeather Senior Meteorologist Tom Kines.
Low river levels at the onset of the thaw and storm may allow ice jam flooding to be contained to low-lying, unprotected areas along the streams.
"There is also a risk of roof collapses in New England, where up to a couple of feet of snow remains and the heavy rain adds more weight," according to AccuWeather Senior Meteorologist Dave Samuhel.