Area cameras and surface observations indicate patchy dense fog across portions of south central and eastern Virginia, including on the Northern Neck. Visibilities are averaging one half to one mile, though some areas have dropped to a quarter mile or less. The densest fog is expected in rural and/or sheltered locations. Visibilities should rapidly improve after 9 AM this morning. Motorists should be alert for sudden changes in visibility due to the areas of dense fog. Drive at reduced speeds and use low beam headlights only.