Then, as temperatures drop tonight to 28, the mix of rain, snow and sleet, will turn to all snow by 3 a.m.
Forecasters expect new snow and sleet accumulation of 2 to 4 inches before ending by 7 a.m. Saturday. Outlying suburbs in Pennsylvania could see up to 7 inches. It will gradually warm to 34 and remain cloudy with another half inch of snow possible.
But Saturday should turn sunny, with a cold, clear night dipping to 14.
Temperatures will rise to 39 on Sunday, meaning much of the snow will start to melt. But then there's another slight chance of snow overnight into Monday, without much accumulation.
The good news: Poconos ski resorts will see new powder, with two to four inches possible today, and an additional six to 10 inches overnight. In total, the Poconos and North Jersey could see more than a foot of snow.
At the Shore, Atlantic City is forecast to receive heavy rain and winds, but snowfall will likely be an inch or less.
Some areas of the Shore closer north, will likely see a bit more snow overnight into Saturday. Seaside Heights - battered by Superstorm Sandy in October - is forecast to receive 3 to 5 inches.
Brick Township, which was slammed particularly hard during Sandy, issued a voluntary evacuation order and officials are urging people to take precautions. Residents in flood-prone areas can relocate their vehicles.
In Ocean County, which was also hit hard, authorities are keeping a close eye on the storm.
"The Ocean County Office of Emergency Management is really monitoring this very closely because a part of this is a coastal storm," said Donna Flynn, a spokeswoman for the office. "So we're certainly keeping an eye on it."
Flynn said the office is coordinating with several agencies to monitor the two storm fronts. Flooding does not appear that it will be a major issue, she said, but there is concern about beach erosion.
"After Sandy, the concern is probably greater than it was before," she said.
The weather service says moderate flooding and "moderate to major" beach erosion is likely in New Jersey and Delaware.
No flooding is expected along the Schuylkill or Delaware rivers, forecasters said. Small streams and poor drainage areas could see some flooding.
But Northern New Jersey, New York, and into New England won't be so lucky. Many of the areas are still reeling from Sandy and fear flooding and more power outages.
The National Weather Service says "the pieces" are coming to together for a major "maybe even historic" storm.
Energy from a low pressure system, or clipper, coming from the Ohio Valley is expected to collide with a low coming northeast, or nor'easter - along the mid-Atlantic Coast tonight.
Sustained high winds - some reaching 65 m.p.h. - could cause blizzard conditions.
In the Philadelphia region, we could see gusts of up to 40 mph inland and 50 mph gusts along the Jersey coast.
The "combination of high winds and wet snow will produce a threat of significant power outages," a weather service briefing says.
Some forecasts are warning the storm could dump up to 3 feet of snow from New York City to Boston and beyond.
Residents there are stocking up on food and water and road crews readied salt and sand.
Airlines have scratched more than 2,600 flights through Saturday, with the disruptions from the blizzard certain to ripple across the U.S.
It could impact Philadelphia International Airport, which is warning that flight operations could be delayed and that travelers should check the status of flights before traveling to the Airport (1-800-745-4283; or http://www.phl.org).
"This one doesn't come along every day. This is going to be a dangerous winter storm," said Alan Dunham, meteorologist for the National Weather Service in Taunton, Mass. "Wherever you need to get to, get there by Friday afternoon and don't plan on leaving."
Snow began falling already this morning in some areas. Widespread power failures are feared, along with flooding in coastal areas still recovering from Sandy.
Amtrak said its Northeast trains will stop running Friday afternoon. The organizers of New York's Fashion Week , a closely watched series of fashion shows held under a big tent , said they will have extra crews to help with snow removal and will turn up the heat and add an extra layer to the venue.
Blizzard warnings were posted for parts of New Jersey and New York's Long Island, as well as portions of Massachusetts, Rhode Island and Connecticut, including Hartford, New Haven, Conn., and Providence. The warnings extended into New Hampshire and Maine.
The AP contributed to this report