More than a dozen wildfires are burning in California right now — some with so much intensity, they’re creating cloud formations usually seen over erupting volcanoes.
The clouds, known as pyrocumulus, are cumulus clouds that form when hot air and smoke are ”released into the sky during wildfires and volcanic eruptions”, according to LiveScience. Pyrocumulus clouds, which also formed during the Thomas Fire in December 2017, have been spotted coming from the Carr Fire near Redding, the Ferguson Fire in Mariposa County, the Mendocino Complex fires and the Cranston Fire near Idyllwild, according to social media posts from meteorologists and other observers.
Regular cumulus clouds form when the sun heats up the ground and creates warm air, which rises and then condenses into a cloud, according to CNN.
Pyrocumulus clouds form at a much faster rate, according to LiveScience. They “can even produce lightning and cause the winds to gust and blow in different directions,” CNN meteorologist Brandon Miller said. The clouds can also produce rain that will sometimes put out the fire.
Nick Nauslar, a NOAA research scientist, said the clouds can create dangerous weather systems and potentially more wildfires, Live Science reported.
Pyrocumulus clouds that appear above volcanic eruptions produce lots of steam and appear black or dark brown from the volcanic ash, according to Outside Magazine. Pyrocumulus clouds that appear above wildfires “are usually dark gray due to the smoke and ash,” Outside reported.
On social media, meteorologists and observers alike have posted photos of pyrocumulus clouds they’ve spotted over the fires.
Sobering satellite imagery at sunset this evening depicting (multiple) massive pyrocumulus plumes and widespread smoke coverage across northern California. #CarrFire exploding again, with new fires in Mendocino County (#RanchFire, #RiverFire) and elsewhere. #CAwx #CAfire pic.twitter.com/VbXFUgMzYz— Dr. Daniel Swain (@Weather_West) July 28, 2018
Another breathtaking example of a pyrocumulus cloud over the #CarrFire this week -- generated when the fire is so hot the air explodes upward, creating a new local weather pattern that can bring strong winds, lightning, and... new fires.— Eric Holthaus (@EricHolthaus) July 30, 2018
Photo: @TMFPD pic.twitter.com/hXvtElAQba
How crazy is this?— Kimberly Kolliner (@KimberlyKTVL) July 28, 2018
A pyrocumulus cloud formed from the #CarrFire...
If it gets big enough it can create a microclimate, which means more winds and the possibility for lightening.@Milt_Radford @RandiBurnsKTVL @AutumnKTVL
Can you help us understand how these form? pic.twitter.com/PBQx6PDdkw
Looks like #FergusonFire is generating another pyrocumulus cloud this afternoon per #GOES16 imagery. Smoke is only gradually spreading out as winds aloft are rather light, with worst air quality impacts in the immediate vicinity of the fire. #CAwx #CAfire pic.twitter.com/EdtG1zpscm— Daniel Alrick (@SFmeteorologist) July 17, 2018
Time lapse of the intimidating pyrocumulus clouds towering over the burning Idyllwild hellscape, bringing with them lightning, high winds and turbulence, making it tough for aircraft to fight the fire. #CranstonFire pic.twitter.com/fzFumNIvgk— Jacob Margolis (@JacobMargolis) July 26, 2018
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Smoke from the Carr Fire and other wildfires in California and Oregon has drifted north to Washington and across Idaho, creating hazy skies across the region. Take precautions if you're sensitive to air pollution.