State College, Pennsylvania – Drivers across central Pennsylvania could encounter dangerously low visibility during the early morning commute as dense fog spreads across the region, reducing visibility to as little as one-quarter mile along several major highways including US-322, I-81, and I-99.
According to the National Weather Service in State College, a Dense Fog Advisory remains in effect across much of central Pennsylvania until 7 AM Thursday. Visibility across the region may drop to 0.25 miles or less, creating hazardous travel conditions during the early morning hours.
Cities impacted by the advisory include State College, Harrisburg, Lancaster, Altoona, York, Chambersburg, Carlisle, Lewistown, and Lock Haven. Motorists traveling along US-322 near State College, I-99 through Blair County, and I-81 near Harrisburg could encounter rapidly changing visibility conditions during the morning commute.
Fog tends to thicken in valleys and low-lying areas across the Susquehanna River basin and surrounding Appalachian ridges. Drivers may experience relatively clear conditions in one location before quickly entering dense fog banks only a few miles away.
Secondary roads and rural highways across counties including Centre, Blair, Huntingdon, Mifflin, Dauphin, Lancaster, and York may also see sudden visibility reductions, especially near rivers, creeks, and farmland where moisture is trapped close to the ground.
Transportation officials urge drivers to reduce speeds, increase following distance, and use low-beam headlights while traveling in fog. High beams can reflect off moisture in the air and worsen visibility. Allowing extra time to reach destinations is recommended during the morning commute.
Conditions are expected to gradually improve after sunrise as daylight increases and light winds begin mixing the lower atmosphere. However, patchy fog may linger in valleys through mid-morning before fully dissipating.
