A series of fires in Northern California's wine country is shaping up to be one of the worst firestorms in state history. An estimated 20,000
The cause of the fires remained under investigation on Monday afternoon. But a weather phenomenon known as the "Diablo winds" is partly responsible for the widespread devastation.
It's peak wildfire season in California, and October is a notoriously challenging month for firefighters. Typically, sea breezes come off the Pacific Ocean and make landfall. In the fall, high pressure builds in the Great Basin — a huge swath of land that spans much of the western US — and causes wind to blow in an opposite direction, the Los Angeles Times reported.
Air descends from high elevations in Nevada and Utah down to sea level in Northern California, compressing and warming in the process. Winds — known as "Diablo winds" form.
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In California's wine country, these especially dry winds arrived overnight,
Fires spread from ridge top to ridge top overnight, stretching over eight California counties.
You can see gusts of wind blowing through the vineyard at this Napa Valley winery.
California Governor Jerry Brown issued a state of emergency for Napa, Sonoma, and Yuba counties on Monday morning — a declaration that mobilizes the California National Guard.
"This is really serious. It's moving fast. The heat, the lack of humidity, and the winds are all driving a very dangerous situation and making it worse," the governor said at a morning news conference. "It's not under control by any means. But we're on it in the best way we know how."