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What is super fog?

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Thursday morning’s deadly crash in Volusia County on I-95 being linked to low visibility caused by super fog. Super fog is combination of both condensed water vapor and wildfire smoke.

There are many mornings we wake up this time of year to dense fog. When that fog is mixed with wildfire smoke it enhances the effects, in worst cases even your hand in front of you could be hard to see. This makes driving extremely dangerous and we move through dry season, the chances we see super fog in Southwest Florida increases.

NWS Tampa Meteorologist Dan Noah spoke about what makes super fog so dangerous.

“In Florida, about every 5 years, we have a terrible super fog accident on the interstate or some of our bigger highways with multiple fatalities and numerous vehicles,” said Noah.

Florida has a history of similar deadly pileup crashes. After an incident on I-75 in January of 2012, Florida Highway Patrol announced actions to better monitor super fog conditions. In Thursday’s case, FHP says they were not given advanced notice of the prescribed burn in the area. While unclear if that directly impacted the outcome, it shows the dangerous conditions can be, especially if proper notice wasn’t given.

“If we have a leftover burn, the smoke from that burn can combine with the water vapor in air create a lot more fog,” said Noah

For fog or clouds to form, the water vapor needs something to attach to, called condensation nuclei. Smoke only intensities that process.

“If we had a completely clear atmosphere with no particles in it, we wouldn’t have a cloud,” said Noah. “Because the water vapor has to condense on something like a little tiny smoke particle. And with smoke you have some many more particles in the atmosphere for that water vapor to latch onto and reduce the visibility.”

While this accident did happen in Northeast Florida, super fog can happen here in Southwest Florida especially in fog and fire season.

“If you are driving home and you smell smoke and you hear the tv meteorologist saying hey we are going to have fog tomorrow morning,” said Noah. “Just know when you drive by the smokey area tomorrow morning if could be very dense fog or super fog.”