The Shenandoah Valley is bracing for the development of foggy conditions that are expected to impact visibility for residents and travelers alike. The National Weather Service has issued an advisory highlighting the likelihood of dense fog formation, especially during the early morning hours, which could lead to perilous driving conditions on roads and highways. Fog typically arises when the air cools to its dew point, causing water vapor to condense into tiny suspended droplets. This is a common occurrence in the Shenandoah Valley during the cooler months when lower temperatures combine with high humidity, exacerbated by the valley's topography.