Temperatures will surge into the 60s and 70s F from the Ohio Valley to much of the mid-Atlantic United States during the middle of this week.
On Tuesday, the warmup will begin in earnest over the Ohio Valley. Temperatures farther east will begin to rebound.
At peak, temperatures will run 15-20 degree above average for late March.
On Wednesday and Thursday, the peak of the warm in the mid-Atlantic will coincide with the peak of the cherry blossoms in Washington, D.C.
The warmth will likely stop short of records in most locations. For example, the record high in Washington, D.C., is 93 on Wednesday and 85 on Thursday. The record in Philadelphia is 80 on Wednesday and 76 on Thursday.
Temperatures could climb within a few degrees of the record high of 76 in New York City on both Wednesday and Thursday. Record highs are in the lower 80s around Pittsburgh.
Farther north, the warmup will be progressively more limited from Boston to Portland, Maine, and Burlington, Vermont. In northern New England, cold air will hold its ground.
Highs will range from the 20s in northern Maine to the 40s in central upstate New York and the 50s in southern Connecticut on Wednesday and Thursday.
A variety of precipitation will develop along the strong north-south temperature contrast with snow over the northern tier, rain near the Pennsylvania/New York/New Jersey border as well as in southern New England to a wintry mix in the middle.
A dose of chilly air will slice into the warmth on Thursday in the Ohio Valley and then the mid-Atlantic on Friday.
The period from the last few days of March to the middle of April will bring episodes of chilly air and warmth.
"Frequent storms moving through into the middle of April will prevent cold air from taking root in most locations," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
It will get chilly enough for frosts and freezes to occur from the Upper Midwest to the Northeast through mid-April.
"It is possible a chilly episode or two brings the risk of frost as far south as the to interior portions of Maryland, Virginia and perhaps North Carolina during the latter par of week one to week two of April," Pastelok said.
"By the end of April, building warmth from the South and in the northern Plains will meet up over much of the Midwest and mid-Atlantic on a more consistent basis."
Portions of upstate New York and New England will continue to struggle with chill through the end of April.
"You need days with winds from the west-southwest to get it warm and stay warm in New England in the spring, and these may be limited to only a few," Pastelok said.
When winds are from the south and east in New England, often chilly conditions win out and sometimes low clouds and drizzle add to the chill.