A multifaceted winter storm is expected to overspread the Northeast during the first half of the week, bringing traffic-snarling snow, wind and ice to the region.
Some snow and ice moved through the mid-Atlantic on Sunday night ahead of the main storm. However, even more disruptive winter weather is expected to unfold into Tuesday.
The storm will start as freezing rain across a swath of the Ohio Valley and snow in the mid-Atlantic around Philadelphia and State College, Pennsylvania.
On Monday night, snow will overspread much of New York, Pennsylvania and New Jersey while icy conditions plague a swath stretching from central Michigan to the Delmarva, including Detroit, Harrisburg, Baltimore and Philadelphia.
During this time, travel will become increasingly difficult and dangerous as roads become coated in slick snow and ice. Widespread instances of spin-outs and accidents can occur, as well as mounting airline delays.
Snow will continue over much of New York and New England on Tuesday while freezing rain and sleet fall across southern New York, eastern Pennsylvania and New Jersey. Any snow that hasn't been cleared away will become heavier and harder to remove with the added ice.
Even plowed roads can become ice-covered, refreshing dangerous driving conditions from Syracuse to New York City.
"Parts of Pennsylvania could receive 3-6 inches of snow Monday afternoon through Monday night before a change to ice," according to AccuWeather Senior Meteorologist Mike Doll.
"There is potential for 6-12 inches Tuesday through Wednesday from upstate New York to northern New England," he said.
As this ice storm unfolds over the Northeast, travel can become impossible for a time.
"While too early to specify exact ice amounts, there may be enough ice accumulation to coat trees and power lines, leading to power outages and travel disruptions from fallen trees, breaches, and wires," Doll warned.
Farther south, heavy rain will move in to replace icy conditions as milder air inches up the East Coast. Residents of the Ohio Valley and much of the mid-Atlantic, including western Pennsylvania, Maryland the the Delmarva, can expect rain and melting ice and snow to pond on roads and saturate lawns on Tuesday.
Travel delays can arise due to localized flooding, gusty winds and limited visibility.
As the storm moves away on Tuesday night, a changeover to rain is expected along the Interstate 95 corridor from Washington, D.C. to Boston. Farther inland, a cooldown will lead to another round of wintry precipitation.
This means that despite drier weather on Wednesday, roads and sidewalks can still be slick as temperatures fall.
Download the free AccuWeather app to stay up-to-date on your local forecast, warnings and advisories. Plan ahead now to avoid travel during wintry conditions.
"If anyone has to be out during the storm, it is advisable to heed all travel restrictions and guidelines on area roads," Doll said.