Pittsburgh, PA – A Freezing Fog Advisory is in effect this morning for large portions of Northwest and Western Pennsylvania, where forecasters warn of dangerously low visibility and light icing through 9 a.m. Thursday.
According to the National Weather Service in Pittsburgh, visibility may drop to one-quarter mile or less in dense freezing fog. The advisory includes Mercer, Venango, Forest, Lawrence, Butler, Clarion, Jefferson, Armstrong, Westmoreland, and Indiana counties. Cities such as Butler, Hermitage, Greensburg, Indiana, New Castle, Sharon, and Kittanning are all within the affected area.
Drivers may encounter slick spots—especially on bridges, overpasses, and untreated secondary roads—where a thin glaze of ice can quickly form in subfreezing temperatures. Forecasters caution that even minimal icing can make for treacherous travel before sunrise, particularly along rural routes and higher elevations in Indiana and Westmoreland counties.
Motorists are urged to reduce speeds, use low-beam headlights, avoid sudden braking, and leave extra distance between vehicles. The combination of freezing fog and low visibility may lead to delays along major travel corridors including I-79, I-80, Route 422, the PA Turnpike, and local commuter routes into the Pittsburgh metro.
Conditions are expected to gradually improve after 9 a.m. as temperatures rise above freezing and fog dissipates. However, isolated slick spots may linger longer in shaded or elevated terrain.
Residents are encouraged to stay alert for changing roadway conditions and allow extra travel time during the morning commute. The NWS will continue to monitor the situation and issue updates as needed.
