Wildfire explodes to more than 52,000 acres in 1 day

A California wildfire exploded overnight and into Thursday, with the massive blaze prompting evacuation orders and a highway closure.

The Madre Fire ignited Wednesday afternoon in San Luis Obispo County, according to Cal Fire. It has since grown to more than 52,500 acres and is 5% contained as of Thursday afternoon, fire officials said.

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The fire — the largest in California so far this year, according to Cal Fire data — is burning in a largely rural area in the Los Padres National Forest near Highway 166, officials said.

Evacuation orders have been issued near Highway 166 in San Luis Obispo County. The highway is closed from U.S. 101 near Santa Maria to Perkins Road in the New Cuyama area of Santa Barbara County, according to the California Department of Transportation.

All Bureau of Land Management lands in Carrizo Plain National Monument are closed to public access due to the fire, the agency said Thursday.

Approximately 50 structures are threatened, according to Cal Fire.

Officials warned that the fire has a high rate of spread.

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“With the current weather, terrain, and fuel conditions this fire has seen exponential growth in less than 24 hours in multiple counties surrounding the San Luis Obispo County area,” the U.S. Forest Service – Los Padres National Forest said on social media Thursday morning. “Smoke impacts will be far-reaching.”

The cause of the wildfire is under investigation.