Snow, frigid air headed to region in coming days

March weather more like January

The official start of spring is just over two weeks away, but winter still has some fight left in it.

And it’s coming with a one-two punch.

A storm expected to hit the region Sunday morning and continue throughout the day could dump as much as half a foot of snow before it ends.

After that, Western Pennsylvania will face another bout with frigid air that could drop temperatures into the single digits.

The National Weather Service has issued a winter storm warning for Allegheny, Westmoreland, Washington and several other counties in effect from 10 a.m. Sunday to 1 a.m. Monday. Butler, Beaver and other counties to the north will be under a winter weather advisory for that same time period.

The difference between the warning and advisory is “how much snow you’re looking for in a 12-hour period,” said Lee Hendricks, a meteorologist with the weather service in Pittsburgh. A winter storm warning is issued when an area is expected to receive more than 3 inches of snow in 12 hours or 6 to 8 inches in 24 hours.

Allegheny and other counties to the south could see around 4 to 6 inches of snow Sunday. Counties to the north could see 3 to 5 inches.

Areas north of Allegheny County will not see as much snow because this storm is working its way up the Appalachian Mountains toward the East Coast where it may turn into a nor’easter.

“Everybody is always used to the system coming down from the north or northwest,” Mr. Hendricks said.

Though the snowstorm is coming from the south, the air that follows it will be coming from the north, once again plunging the region to arctic-like temperatures.

Low temperatures on Monday, Tuesday and Wednesday have a chance to drop into the single digits. Highs on those days will only reach the 20s.

“Thursday, we finally hit the 30s,” Mr. Hendricks said.

With the improvement, however, comes another round of snow.

The National Weather Service has issued a winter storm warning for Allegheny, Westmoreland, Washington and several other counties in effect from 10 a.m. Sunday to 1 a.m. Monday.