Raging California wildfires are creating their own weather

Wildfires tearing through Northern California are creating their own weather systems, making them even more dangerous and unpredictable, meteorologists say.

Fire-generated tornadoes, pyrocumulus clouds help fires spread and boost unpredictability

A firefighting helicopter makes a water drop as the sun sets over a ridge burning near Redding, Calif., in efforts against the Carr Fire on July 28, 2018. (Hector Amezcua/The Sacramento Bee via Associated Press)

Wildfires tearing through Northern California, destroying homes and forcing people to flee, are creating their own weather systems, making them even more dangerous and unpredictable, meteorologists say.

In Redding, where the ongoing Carr fire has burned more than 800 homes and killed six people, firefighters have reported vortexes of fire.

"That's literally fire behaviour that we've not experienced, or seen or witnessed in a generation here in California," Jonathan Cox, Northern California battalion chief for Cal Fire, said Monday.

Other firefighters reported winds ripping trees off the ground and throwing them across the street into homes.

At a news conference on Friday, Cal Fire director Ken Pimlott described the fire activity as almost like a "tornado."

Such fire tornadoes, referred to as firenadoes, occur when extremely hot fires pull the surrounding air in like a vacuum, forming funnels of wind, said CBC meteorologist Ryan Snodden on CBC's The National on Monday.

"They're strong enough to rip roofs off of houses, trees out of the ground, and they can start new fires by stirring up ash and throwing up embers far into the air."

Firefighters say wind has been a major contributor to the fires' spread this year.

But fires can also form huge mushroom clouds called pyrocumulus clouds that generate thunderstorms, lightning and localized winds, Snodden said.

"It can be dangerous because these big clouds create their own weather… That makes the fire even more volatile and hard to predict than it was."

He said the weather forecast isn't looking good from a fire perspective — the National Weather Service warns of continuing extreme heat, low humidity and gusts of up to 40 km/h.

Cox said wildfires like these are the "new normal" in California.

"We've seen larger and more destructive fires year over year and unfortunately, this year doesn't look to be any different."

Destructive California wildfire creates its own weather system

5 years ago
Duration 4:13
The destructive Carr wildfire in California is so big, it has created its own micro weather system, making it harder to predict what it will do next.

With files from The Associated Press