Drivers might want to leave a little early on their Friday morning commute since they may face foggy conditions along the road.

The National Weather Service has issued a Dense Fog Advisory for northwest, southwest, and western Pennsylvania, east-central Ohio, and northern and the northern panhandle of West Virginia.

The advisory is in effect until 9 a.m. in an area that includes Trumbull, Mahoning, and Columbiana counties in Ohio, as well as Mercer, and Lawrence in Pennsylvania.

Visibility could be one-quarter mile or less in dense fog, causing hazardous driving conditions.

Drivers are advised to slow down, use their headlights, and leave plenty of distance ahead of them.