Crews battling wildfires across California are getting more manpower and some help from Mother Nature.

The Lockheed Fire, which has been burning since Wednesday, blackened about 2,800 acres, or 4.4 square miles, in Santa Cruz County. It's forced thousands of people to leave their homes in the Santa Cruz Mountains.

The area's rugged terrain and limited access are making it difficult for the hundreds of firefighters currently at the scene. But more firefighters, six helicopters and six fixed-wing aircraft were expected today.

Higher humidity from overnight forecasts of fog, and light wind are also welcome news to ground crews.

There were no reports of injuries related to the fire, whose cause is under investigation.