A red flag fire warning is in effect through early Wednesday east of Interstate 15 in San Diego County, where Santa Ana winds will blow over land slipping into drought, the National Weather Service said.

San Diego Gas & Electric has notified nearly 117,500 customers that it may have to temporarily shut off power to reduce the risk of wildfires.

Most customers live in various parts of North County and East County, but some are located along the U.S.-Mexico border, from Imperial Beach and San Ysidro to eastern Chula Vista.

Moderate to strong Santa Ana winds are expected to blow through the inland mountains, valleys and foothills beginning Monday afternoon and increasing through Tuesday.

Forecasters say winds could reach 63 mph in Campo and 56 mph in Escondido and Alpine. Driving on Interstate 8 east of Alpine could be difficult.

Relative humidity will fall below 20% Monday afternoon and fall to as low as 5% on Tuesday and Wednesday, forecasters said. Such conditions encourage the spread of forest fires.

Coastal areas will also experience low humidity, but it will not be as bad as East County.

The Santa Anas will arrive from the east at a precarious time. The county has received only a fraction of its seasonal rainfall. San Diego International Airport has been particularly dry, recording just 0.13 inches of rainfall since October 1st. That’s about 1.50 inches below average.

Forecasters don’t expect the county to receive significant rain until Dec. 15 and likely until Christmas.

California has experienced several rainfall events since early November, but the storms remained mostly in the northern part of the state. Forecast models suggest that the trend could continue into January.

Originally published: December 8, 2024 at 2:26 pm PST