Rare flash freeze on region's roadways despite warmer air temperatures causes several accidents

PITTSBURGH — A rare flash freeze on the region’s roadways while temperatures were well above freezing caused several vehicle accidents Wednesday morning.

Black ice formed Wednesday morning because the ground temperature was still so cold after several days of frigid temperatures, even though air temperatures were warmer.

National Weather Service meteorologist Fred McMullen said this occurrence is only seen nationwide once every five years, and it’s even rarer in Pittsburgh.

"This is the first time I've seen a situation like this happen in about 15 years," he said.

Clouds will keep the ground warmer, but the skies cleared overnight, allowing the ground temperature to drop below freezing. This caused a problem, since the ground was wet from rain Tuesday night.

East Street on the North Side was blocked off until salt was put on the road. Butler Street in Lawrenceville was backed up with traffic because of an accident due to slick road conditions.

Cox Media Group