920 AM MDT Thu Mar 28 2019 Northeast Johnson County-Southeast Johnson County- Natrona County Lower Elevations- Including the cities of Buffalo, Kaycee, and Casper 920 AM MDT Thu Mar 28 2019 ...Areas of Dense Fog over portions of Natrona and Johnson counties this morning... Areas of dense fog stretch from northern Natrona County near 20 mile Hill northward to the Interstate 90 corridor. Visibilities of 1/2 mile or less will be possible at times. Motorists are urged to watch for rapid changes in visibility. Slow down and use low beams when encountering fog.