Pittsburgh, Pa. – Motorists across western Pennsylvania should slow down now as visibility could drop below one-half mile on I-376, I-79 and the Pennsylvania Turnpike between 1 a.m. and 7 a.m. Monday, creating hazardous conditions for the early commute.
According to the National Weather Service in Pittsburgh, calm winds combined with wet ground from recent rain and melting snow will allow areas of fog to develop late Sunday night and persist into Monday morning. The highest probabilities for visibility under a half mile occur between 1 a.m. and 4 a.m., reaching 70% in Pittsburgh and up to 90% in Butler. Communities including Beaver, New Philadelphia and Zanesville show 70% to 80% chances of dense fog before sunrise.
Low-lying valleys and river corridors near the Ohio, Monongahela and Allegheny rivers are especially vulnerable. Drivers along I-70 near Washington, I-76 across Westmoreland County and Route 28 north of the city could encounter sudden drops in visibility with little warning.
PennDOT crews are not reporting closures, but conditions can change quickly. Use low-beam headlights, reduce speed and increase following distance. Avoid high-beam lights, which reflect off fog and worsen visibility.
Fog may linger for several hours after sunrise Monday, especially in sheltered areas. Conditions should gradually improve by late morning, but additional advisories could be issued if visibility drops further overnight.
