NEW YORK (AP) - Sandwiched between days that felt like spring last week and the official start of spring next week, a "life-threatening" nor'easter is poised to bring a reminder that winter isn't over yet, with blizzard conditions and a blanket of heavy snow expected in the mid-Atlantic and Northeast.
Meteorologists were calling for snowfall totals as high as 20 inches in New York City from the storm's start late Monday through Tuesday evening. The National Weather Service warned that blizzard conditions of wind gusts over 35 mph and low visibility would extend from the Philadelphia area to Maine.
The weather service's office near Philadelphia called the storm "life-threatening" and warned people to "shelter in place." Coastal flooding was also predicted.
Travel was sure to be dismal: About 5,000 Tuesday flights were canceled as of late Monday afternoon , Amtrak canceled and modified service up and down the Northeast Corridor and motorists were urged to stay off the roads.
In New York City, the above-ground portions of the subway system were being shut down from 4 a.m. Tuesday. Connecticut Gov. Dannel P. Malloy imposed a statewide travel ban beginning at 5 a.m.
The forecast prompted early decisions to close schools on Tuesday in New York City, Philadelphia, Boston and many places in between.
New York City Mayor Bill de Blasio urged residents to avoid unnecessary travel and help keep the roads clear. "We're preparing for a significant storm on Tuesday, and New Yorkers should also prepare for snow and dangerous road conditions," de Blasio said.
The storm comes a week after the region saw temperatures climb into the 60s. Spring officially starts on March 20.
Bank teller Jana White said her plans for riding out the storm include "lots of hot chocolate and a couple of sappy movies." The 23-year-old Trenton, New Jersey, resident said she expects to get Tuesday off work.
"It's a reminder that winter is always ready to take shot at you, so you have to stay prepared," she said. "We've got food and snacks and drinks, so as long as the power stays on we should be in good shape."
The heaviest snowfall was expected Tuesday morning through the afternoon, with snowfall rates as high as 2 to 4 inches per hour. Coastal flood warnings were in effect from Massachusetts to Delaware.
Boston could get 12 to 18 inches, with isolated amounts of up to 2 feet across northeastern Massachusetts.
In Philadelphia, where up to a foot of snow could fall, crews began treating some area roadways on Sunday.
Farther south in the nation's capital, where the National Cherry Blossom Festival is scheduled to start Wednesday, snow accumulations of 6 to 8 inches were expected.
That led German Chancellor Angela Merkel to postpone her trip to Washington for her first face-to-face meeting with President Donald Trump. Merkel had been scheduled to arrive late Monday night for meetings with Trump on Tuesday. The White House said the meeting was rescheduled for Friday.
Baltimore is expected to get 8 to 12 inches.
The storm also changed plans for some teams competing in the NCAA tournament: Villanova, the top overall seed in the men's tournament, left Philadelphia early to get ahead of the storm.
As the East Coast prepared, the Midwest was hit with snow, forcing a number of flight cancellations. In Chicago, the forecast called for 3 to 6 inches of snow, the city's first significant snowfall since mid-December.
Southern portions of Minnesota got more than 9 inches of snow in some areas. In Michigan, utility crews worked in the snow to restore power to those still without electricity following high winds that hit the state on Wednesday.
Associated Press writer Bruce Shipkowski contributed to this report from Trenton, New Jersey.