A new plunge of cold air will produce snow showers in some parts of the Midwestern and Northeastern states and accumulating snow in others this week and into the weekend.
In come cases the cold air will rival that of nights early in the week, including parts of the interior South. The cold will threaten blossoming fruit and ornamental trees.
The air will be cold enough to allow showers to fall as a mix of rain, ice and snow in some areas and mostly snow in others.
It can snow when temperatures are well above freezing, particularly in the spring. Even though temperatures near the ground may be relatively high, the air aloft is often very cold in the spring. The cold air aloft increases the chance of snow or an icy mix surviving the trip thousands of feet to the ground.
In most cases, the brief snow showers will be a nuisance and depart before an accumulation occurs. However, where it snows for more than a few minutes, an accumulation is more likely.
Intertwined with the wintry showers of varying intensity will be a storm system that arrives on the scene after the showery pattern has commenced.
"The storm rotating through the cold air invasion could bring a period of steady snow to parts of the Midwest and Northeast," according to AccuWeather Chief Meteorologist Elliot Abrams.
A relatively narrow zone could experience a small accumulation of slush or up to a few inches of snow.
This is possible from parts of Wisconsin, Illinois, Indiana, and Michigan to several counties in Ohio, the West Virginia mountains and parts of western Pennsylvania and Maryland late Friday into Friday night. Cities that could receive small accumulations include Chicago, Detroit, Cleveland and Pittsburgh.
On Saturday, a steadier mixed precipitation could extend eastward across portions of northern Virginia, northern Maryland, Delaware, southern Pennsylvania, southern and eastern New Jersey and southeastern New York state. Cities that could receive some wet snowflakes include Washington, D.C., Baltimore, Philadelphia and New York City.
Only if that storm strengthens would the wintry mix switch over to a period of steady, accumulating snow in the coastal mid-Atlantic.
"A greater potential exists for a period of steady, accumulating snow in southeastern New England during Saturday night," Abrams said.
In this area, similar to the central Appalachians and parts of the Midwest, slightly lower temperatures at night may be the tipping point for up to a few inches of slush.
People in Boston; Providence, Rhode Island; Hartford, Connecticut; and Portland, Maine; could have to haul out the snow shovels once again.
Motorists traveling on the highway should be on the lookout for rapidly changing visibility and road surface conditions.