Pittsburgh's Christmas Winter Storm: Latest Snowfall Predictions

PITTSBURGH, PA — Merry Christmas, Pittsburgh. Santa is about to bring you a significant snowfall.

The city awoke to moderate to heavy rainfall on Thursday with temperatures hovering around 50, but conditions will change dramatically this evening. The National Weather Service has issued a winter weather advisory for Pittsburgh and most of southwestern Pennsylvania; a winter storm warning is in effect for the ridges in Westmoreland and Fayette counties.

The advisory is in effect from 7 p.m. Thursday until 1 p.m. on Christmas Day. The weather service predicts four to six inches of snow during that period.

Other forecasting services had differing amounts of snow predicted on Wednesday, but all were similar as of Thursday morning. The Weather Channel is forecasting three to five inches for the region, and State College-based AccuWeather is predicting three to six inches.

Expect much colder weather on Christmas, with temperatures struggling to reach 20. A gradual warmup to more seasonable temperatures will occur Saturday and Sunday.

The snow won't be the only issue Thursday evening. Colder air rushing into the region could create a flash freeze situation, making travel extremely hazardous.

PennDOT has announced road restrictions for the Parkway West westbound from the Fort Pitt Tunnel to Interstate 79 beginning at 7 p.m. Thursday. Those restrictions bar the following vehicles from the road:

• Tractors without trailers.
• Tractors towing unloaded or lightly loaded enclosed trailers, open trailers or tank trailers.
• Tractors towing unloaded or lightly loaded tandem trailers.
• Enclosed cargo delivery trucks that meet the definition of a CMV.
• Passenger vehicles (cars, SUV’s, pickup trucks, etc.) towing trailers.
• Recreational vehicles and motorhomes.
• School buses, commercial buses and motor coaches.
• Motorcycles.

Allegheny County public works director Stephen Shanley said the county will deploy at least 24 salt trucks installed with plows as soon as snow begins to accumulate on roads. Pretreating the roadways with salt is not an option because of rain preceding the snow.

"We will continue to monitor the forecast and adjust our plans, as needed, to ensure continual coverage of our roads throughout the storm," Shanley said. "That might include bringing in more drivers."