Clearing skies, light winds and wet ground may combine to produce dense fog across a wide swath of Indiana and Kentucky Thursday night and Friday morning, the National Weather Service says.
The area where fog might be a problem stretches from southern Indiana to the Kentucky-Tennessee line. It includes Lexington.
The fog will form overnight and be thickest around dawn Friday. Visibility could be limited to less than half a miles.
Motorists are advised to use low headlight beams and slow down if they encounter fog.