Madre fire, one of at least a dozen in the state, has burned more than 50,000 acres in San Luis Obispo county

A fast-growing wildfire in central California has become the largest in the state this year, surpassing the size of January’s wildfires that devastated parts of Los Angeles, as the flames spread in hot, windy conditions.

The Madre fire had exploded to more than 50,000 acres by Thursday morning, after breaking out in San Luis Obispo county on Wednesday afternoon and tearing through grasslands as dry. Extreme heat has raised the fire risk for large portions of the state before the Fourth of July holiday.