A fast-moving wildfire in Southern California has rapidly burned through more than 20,000 acres, fueled by powerful northeast winds. Governor Gavin Newsom has declared a state of emergency, mobilizing additional firefighting resources and urging Californians to prepare for potential evacuation orders.

After the Mountain fire ballooned to more than 20,000 acres in less than 24 hours, improving weather conditions helped crews contain more of the blaze on Saturday.

Calmer winds helped California firefighters battle the once out-of-control Mountain Fire on Friday as they continued to defend homes from the destructive blaze, officials said.