Some of the large, intense wildfires in California may be the state’s first mega-fires.
The Valley Fire in Lake County burned 40,000 acres in less than 12 hours. The Butte Fire doubled in size overnight. The Rough Fire in the Sierra National Forest has now burned more than 139,000 acres.
A wildfire’s rate of spread, size and intensity are all characteristics of mega-fires.
"Some people really criticize the word mega-fire because they say ‘oh you’re just making something up’ but they’re different," says UC Berkeley fire scientist Scott Stephens. "They’re not the same as 1995 or 2000, these are getting different in terms of their ability to move.”
He says fires typically move in a wave pattern, like throwing a rock into a puddle – but not these fires.
“Fires move as waves, but they’re not going to move as waves when you got 10,000 acres in six hours," says Stephens. "It has to jump, so that spotting potential, the live fuel moisture, dead fuel moisture and then the wind. The wind throws those embers downwind, that sets it up for a real severe run like that.”
Stephens says California is seeing wildfires in recent years unlike any seen before. He says the drought and forest mismanagement are helping fuel mega-fires.