The National Weather Service Pittsburgh issued a dense fog advisory for parts of Pennsylvania, Ohio and West Virginia that includes Butler County, which will be in effect until 11 a.m. Wednesday, Jan. 24.

A dense fog advisory is in effect until 11 a.m. Wednesday, Jan. 24 for parts of Pennsylvania, Ohio and West Virginia, including Butler County.

Visibility has decreased to a quarter mile or less in portions of the affected area, which led to the advisory for the fog, according to the National Weather Service.

The service is advising commuters to drive with caution this morning. The fog is expected to dissipate by mid morning as rain overspreads the area.