After a mild morning, rapidly-falling temperatures caused rain to turn over to sleet and snow and was accompanied by heavy winds.
The freezing conditions have caused slick spots and black ice on part of roadways and heavy winds have knocked out power and caused damage in other areas.
Power was knocked out for a large portion of Robinson Township, forcing the Mall at Robinson to evacuate for a brief period and in the Strip District, six stories of scaffolding collapsed due to high winds.
No one was injured in that incident.
A wind advisory remains in effect for most of the Pittsburgh area through midnight with gusts up to 50 miles per hour expected.
Temperatures will level off around the mid-20s as snow tapers off in the evening.
Temperatures will continue to climb through the weekend, into next week if a possible high around 60 on Christmas Day.