CACHE VALLEY, Utah (ABC4) — A dense and thick fog settled into Cache Valley in northern Utah following Tuesday’s storm, prompting the National Weather Service to issue an urgent advisory to slow down when driving.

The advisory, which expires at 11 a.m. on Wednesday, Nov. 8, warns the fog is so dense, it brings visibility down to less than a quarter mile. Images from a camera on the Utah State University Cache Valley campus shows just how dense the fog is with trees quickly disappearing.

Fog outside the Utah State University campus in Cache Valley (Courtesy: USU)


According to the National Weather Service, there are several different types of fog. One type, known as “Valley Fog” forms in valleys when the soil is still moist from previous rainfall.

As the skies clear from the storm, solar energy exits earth and the temperature begins to cool near or at the dew point, creating the fog. The NWS said it can create a deep fog, sometimes also referred to as a “tule fog.”

The National Weather Service said the low visibility caused by the thick fog has created hazardous driving conditions. Drivers are advised to slow down and use caution when commuting on Wednesday morning.


There are some things drivers can do to help safely navigate the thick and dense fog.

  • Slow down.
  • Stay focused on the road.
  • Leave plenty of space between you and the car in front of you.
  • Follow the lines on the road or the sidewalk.
  • Never use your high beams in a fog.

The National Weather Service warns using high beam lights can actually cause more risk of dangers by creating a glare off the fog. The glare makes it harder to see what’s ahead on the road and decreases already low visibility.

In extreme cases where visibility is near zero, NWS said the best course of action is to turn on your car’s hazard lights and pull off to a safe location such as a parking lot. If there is no parking lot, NWS recommends pulling over to the side of the road as far as possible and turning off all lights except for hazards.