National Weather Service United States Department of Commerce

Fog Infographics


Pictured: Car driving in fog.  Text: In dense fog, you only have seconds to react!
Fog Safety - Disabled Vehicle in Dense Fog: 1. Pull well onto the shoulder. 2. Turn off all lights except 'flashers'. 3. If possible leave your vehicle and move away from the road.
The Science of Vallery Fog: 1. Air cools at higher elevations as the ground radiates heat into the atmosphere and space. 2. Cooler air drains downslope into the valley. 3. A cool, stable layer forms the ground, which limits turbulent mixing and traps the cool, moist air.  4. The air near the ground continues to cool until water vapor moleculesd are changed into small droplets of liquid water.