FORESTHILL, Calif. (KRON) — Atmospheric scientists and wildfire experts watched in awe as the Mosquito Fire exploded in size and formed a rotating, billowing pyrocumulus cloud over Placer County forests.
The Mosquito Fire generated its own fire weather on Thursday, an unsettling trend that scientists are increasingly seeing as California wildfires rage with more intensity and speed.
Extreme heat from a rapidly-growing fire produces upward moving air currents that carry water vapor and ash thousands of feet into the sky.
“There is radar/video evidence for a Fire-Generated Tornadic Vortex (Thursday) evening on the SE flank of the Mosquito Fire. Unlike recent cases, this one is clearly cyclonic,” wrote Neil Lareau, a professor of atmospheric science at the University of Nevada Reno.
The Mosquito Fire ignited on Tuesday in Placer County before spreading into El Dorado County.
When a wildfire creates its own weather like the Mosquito Fire, wind and other meteorological conditions are dictated by the fire itself. The Mosquito Fire’s pyrocumulus plume could be seen all the way from Concord in the East Bay.
“What is a pyrocumulus? It’s a cumulus cloud formed by rising air or smoke from an explosive fire. Large pyrocumuli can produce lightning and cause severe turbulence,” the National Weather Service Sacramento wrote on Twitter.
Cal Fire officials wrote in a Friday morning update, “Today the Mosquito Fire showed extreme fire behavior and growth, more than quadrupling in size to over 4,000 acres. The weather in the fire area will continue to be extremely hot and dry overnight and into tomorrow. Combined with very low fuel moistures fire conditions are likely to replicate today’s behavior during the overnight period and into tomorrow’s operational period.”
On top of blanketing Northern California in smoke, flames are threatening 3,600 homes in Placer and El Dorado counties. The fire is currently 0 percent contained, according to Cal Fire.
“It is incredibly important all those who receive an evacuation order leave the area immediately and it is recommended that those in an evacuation warning zone leave the area as well,” Cal Fire officials wrote.
Earlier this week, flames jumped the American River, burning structures in the mountain hamlet of Volcanoville and moved closer to the towns of Foresthill, home to about 1,500 people, and Georgetown, population of 3,000.
David Hance slept on the porch of his mother’s Foresthill mobile home when he woke up to a glowing red sky early Wednesday morning and was ordered to evacuate. “It was actually fricking terrifying, cause they say, ‘Oh yeah, it’s coming closer,’” he said. “It was like sunset in the middle of the night.”
The fire’s cause remains under investigation.
The Associated Press contributed to this report.