How super fog forms and why it can strike without warning

‘It's like you have perfect visibility and then somebody puts their hand in front of your eyes,’ NWS meteorologist Kevin Rodriguez said.

Troopers said three people were killed in several multi-vehicle crashes during dense fog on Interstate 95 in Central Florida on Thursday.

Kevin Rodriguez, a meteorologist at the National Weather Service in Melbourne, Florida told FOX Weather it's believed a rare phenomenon called super fog played a role in the tragedy.

Rodriguez said that super fog takes place when fog combines with smoke and in many circumstances, wildfire smoke is a contributing factor.

"So when the fog is forming, there are all these small particles in the atmosphere, and it just allows the fog to get much denser and over a more large, widespread area," Rodriguez said.

The National Weather Service stated "Super fog forms when a mixture of smoke and moisture released from damp smoldering organic material such as brush, leaves and trees, mixes with cooler, nearly saturated air. Visibility is lowered to less than 10 feet."


The NWS believes smoke produced by a prescribed burn that took place on Tuesday along Interstate 95 in New Smyrna Beach helped contribute to the super fog.

"There was some still some smoldering and some smoke was leftover. And it doesn't have to be a lot, but it can get trapped near the surface, especially overnight," Rodriguez told FOX Weather.

"It's like you have perfect visibility and then somebody puts their hand in front of your eyes."

The U.S. Department of Agriculture says super fog can be a threat to motorists at any time of the time, especially in parts of the southern United States.

While encounters with super fog are rare the NWS suggests drivers be aware of steps they can take if they find themselves in the thick clouds. 

Experts suggest:

  • Drive with lights on low beam
  • Reduce speed and allow for plenty of room between themselves and other vehicles
  • Avoid crossing traffic
  • Turn on wipers and defroster to obtain maximum vision
  • Listen for traffic that is not visible to the eye