GOLETA, Calif. — A wildfire burning Tuesday on Southern California mountains north of Santa Barbara forced as many as 6,300 people from their homes, but an approaching storm offered hope that the flames would be doused, authorities said.

The so-called Cave fire was a threat to an estimated 2,400 structures, Santa Barbara County fire spokesman Mike Eliason told KEYT-TV.

By Tuesday evening, most of the evacuated were allowed to return to their homes. About 4,000 of the evacuees were given permission when authorities reduced the size of the evacuation zone.

The National Weather Service said rain was expected to reach the area by midnight.

#CaveFire- A Cal Fire S-2 makes a phos-chek drop near a home on the east side of Painted Cave Road Tuesday morning in Santa Barbara County & smoke rises above the Los Padres NF with the Pacific Ocean in the distance. pic.twitter.com/nlRRnsBdMp — SBCFireInfo (@EliasonMike) November 26, 2019

The fire started at about 4 p.m. Monday in Los Padres National Forest as winds gusted up to 30 mph.

By Tuesday morning it was estimated at more than 6 square miles with no containment. No homes had been lost and there were no injuries, Eliason tweeted.

The fire was mainly burning through dry, brushy canyons and ridges of the Santa Ynez Mountains but evacuations were ordered in populated foothill areas.

Firefighters battle flames along Highway 154 near Santa Barbara, Calif., on Nov. 26, 2019. Noah Berger / AP

A 1990 wildfire in the same area destroyed more than 400 homes.

Firefighters were told during a morning briefing that the area had not received any rain in 180 days and vegetation was ready to burn, as was demonstrated by the fire’s exponential growth in its early hours.

The firefighters were cautioned that roads into the rugged area may be too narrow for their engines, and that many residents had not left.

The arrival of an expected low pressure system and its accompanying rain also posed hazards ranging from shifting winds to debris flows from steep mountainsides, the firefighters were told.

As much as an inch of rain was expected in the area, and crews were warned to not drive across flowing water.

The dangers of the cycle of fire and flood is a raw memory in the region.

In January 2018, a downpour on recently burned slopes just east of Santa Barbara unleashed massive debris flows that devastated the community of Montecito, destroying homes and killing 23 people.