Fire danger prompts SDG&E to shut down power to at-risk communities

SAN DIEGO – With heightened fire danger in Southern California, San Diego Gas & Electric started shutting down power in at-risk areas including Descanso Tuesday.

The unplanned "cautionary power shutdown" took place at 8:08 a.m.  Tuesday in communities of Descanso, Green Valley Falls, Cuyamaca, Viejas, and Boulder Creek, according to SDG&E officials. The outage was expected to leave around 90 customers without power through Friday afternoon.

Residents are asked to call 911 to report any power lines that have fallen and to stay away from them.

The red flag fire warning prompted by gusty Santa Ana winds and low humidity levels remained in effect Tuesday for much of San Diego County as a wildfire driven by similar conditions tore through Ventura County north of Los Angeles.

A high wind warning also remained in effect Tuesday, with the red flag warning set to expire late Thursday night and the high wind warning expected to expire Thursday afternoon, according to the National Weather Service. But the Santa Ana winds could persist into Friday or Saturday, which would likely mean an extension of both warnings.

Photos: Wind-fueled wildfires destroy SoCal neighborhoods

The NWS issued the red flag warning for the San Diego County coastal area, inland valleys and mountains, including the Palomar and Descanso Ranger Districts of the Cleveland National Forest.

Tuesday and Wednesday, sustained winds are expected to be between 20 and 30 mph with gusts up to 55 or 60 mph, the NWS said. But forecasters now believe Thursday and Friday pose the most significant fire risks, with isolated gusts of 70 to 80 mph possible Thursday.

Helping somewhat to mitigate the fire danger this week will be the relatively mild weather. High temperatures Tuesday in San Diego County will be 70 to 75 degrees at the beaches, inland and in the western valleys, 61 to 66 near the foothills and 48 to 58 in the mountains.

The fire threat this week doesn't come from high temperatures. Instead, it's the strong winds and humidity levels expected to be in the 7 to 15 percent range Tuesday and the 5 to 15 percent range from Wednesday until Saturday.

The wildfire threat was on full display Tuesday morning in Ventura County, where the "Thomas Fire" was being driven by Santa Ana winds and conditions similar to local conditions. That blaze erupted around 6:30 p.m. Monday and quickly spread, growing to 31,000 acres and destroying at least 150 structures as of 3:45 a.m. Tuesday.

To prepare for the potentially dangerous conditions, both the San Diego Fire-Rescue Department and San Diego Gas & Electric beefed up staffing levels this week. The fire department put several extra strike teams on alert that included 10 brush rigs, five engines, two water tenders and two helicopters. SDG&E officials staged field crews and contract firefighters in areas where winds are expected to be the strongest.