At 3:31 a.m. on Sunday, the National Weather Service released a dense fog advisory in effect until 9 a.m. for Northern Clinton, Northern Centre, Southern Centre, Northern Lycoming, Southern Clinton and Southern Lycoming as well as McKean, Potter, Elk, Cameron, Clearfield, Tioga and Sullivan counties.

The weather service says to expect, "Visibility 1/4 mile or less in dense fog for the northern mountains and along I-80."

"Low visibility could make driving conditions hazardous," says the weather service. "Consider allowing extra time to reach your destination. If driving, slow down, use your low-beam headlights, and leave plenty of distance ahead of you."

Navigating fog: Safety tips by the weather service

When a dense fog advisory is issued for your area, it means that widespread dense f

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