A fog advisory is in effect this morning for much of the Parry Sound-Muskoka region. Environment Canada says fog patches are expected to develop with near zero visibility in areas of dense fog. The fog advisory covers all of Parry Sound, Muskoka, Burk’s Falls, South River, and Dunchurch as well as to the south into Coldwater, Washago, Barrie, Midland, and Orillia. Drivers are asked to be careful as visibility may be significantly and suddenly reduced to near zero. Visibility is expected to improve later this morning as the fog lifts.