Updated at 1:50 p.m. Dec. 7, 2017
Santa Ana winds approaching 90 mph in some areas Thursday kept firefighting agencies on the highest possible alert, led to the closure of several East County schools and prompted utility officials to shut off power to more than 3,000 customers.
“An extreme weather event with high winds and dry conditions is underway in select areas of the region,” San Diego Gas & Electric announced in a prepared statement. “To maintain public safety, SDG&E has begun turning off power to customers in several communities. Current conditions indicate that power may remain out for several days before it can be safely restored.”
Late Thursday morning, a fast-moving wildfire erupted alongside Interstate 15 and state Route 76 in the Pala Mesa area. Within 90 minutes, it had grown to roughly 150 acres and destroyed at least two structures while forcing evacuations and road closures.
The electrical outages took place in rural communities in the northern, southern and eastern regions of the county near Alpine, Boulevard, Julian, Santa Ysabel, Warner Springs, Rincon and Pala.
Throughout the morning, the National Weather Service recorded winds gusts of 88 mph on Sill Hill, 70 mph in Alpine, 69 mph in Valley Center, 65 mph on Viejas Grade, 64 mph in Boulder Creek, 63 mph in Descanso, 59 mph in Campo, 56 mph in Julian, 50 mph in Pine Valley and 47 mph in San Diego Country Estates.
To serve those affected by the outages, the American Red Cross of San Diego County opened emergency shelters in El Cajon and Escondido. The El Cajon shelter was opened at Bostonia Park and Recreation Center, 1049 Bostonia St., while the Escondido shelter was opened at the East Valley Community Center at 2245 E. Valley Parkway.
In preparation for the strong Santa Ana winds and the power outages they were likely to cause, education officials on Wednesday night announced the closures of the Julian Union Elementary School District, Julian Union High School District, Spencer Valley School District and Warner Unified School District.
The National Weather Service’s red flag wildfire and high wind warnings remained in effect throughout the county Thursday, with forecasters predicting wind gusts exceeding 80 mph.
In the North County, a wind advisory was issued advising high-profile trucks to avoid state Route 76 between state Route 79 and Interstate 15.
A “red flag” wildfire warning from the National Weather Service was slated to remain in effect until 8 p.m. Sunday night, having been extended by 24 hours Thursday afternoon. A high-wind warning was set to expire at 4 p.m. Friday.
“The fire potential with this Santa Ana event is extreme,” the Forest Service said on its Santa Ana Wildfire Threat Index page. “Easterly winds of 20 to 45 mph can be expected with gusts exceeding 80 mph over the higher terrain and in the more wind prone areas. Humidity will be in the 5- to 15- percent range. Fires will spread very rapidly through all fuel types. Any new fires will have a high probability of becoming large in a short period of time.”
The conditions expected throughout San Diego County were even more extreme than the dry, windy conditions that fanned the three wildfires that have burned more than 20,000 acres in the Los Angeles area, as well as the 90,000-acre Thomas Fire in Ventura County.
In preparation for the critical conditions, San Diego Gas & Electric cut power at seven locations throughout the eastern portion of the county on Wednesday night leaving roughly 1,350 customers without power.
“An extreme weather event with high winds and dry conditions is underway in select areas of the region,” SDG&E officials said. “To maintain public safety, SDG&E has begun turning off power to customers in several communities. Current conditions indicate that power may remain out for several days before it can be safely restored.”
The San Diego Fire-Rescue Department, Cal Fire and other local agencies have also beefed up staffing this week to handle potential fires.
“Meteorologists at the National Weather Service have not seen models for a Santa Ana event like this in many years,” San Diego Fire Chief Brian Fennessy said over the weekend. “We are being vigilant in up-staffing to protect San Diegans and their property. We ask that residents practice their evacuation plans and be prepared in case of a wildfire.”
Locally, the most critical fire conditions started Wednesday night and continued Thursday morning, with wind gusts expected to peak around 9 a.m. Thursday, forecasters said.
On the upside, mild temperatures are expected to help mitigate the fire danger somewhat, though a warming trend began Wednesday and significant risk will remain due to the strong winds and near-negligible humidity levels, the NWS advised. High temperatures Thursday in San Diego County will be 75 to 80 degrees at the beaches, inland and in the western valleys, 64 to 69 near the foothills and 52 to 61 in the mountains.
But several years of drought coupled with heavy rains last winter have led to significant fire fuel in the form of underbrush and grass, and a lack of recent rainfall coupled with frequent low humidity have dried out that extra fuel, making it ready to burn freely, according to firefighting officials.
The Santa Ana Wildfire Threat Index, which categorizes Santa Ana winds based on anticipated fire potential as extreme, high, moderate, marginal or no rating, predicted that the danger would be extreme Thursday, marginal on Friday and moderate on Saturday and Sunday.
Public safety officials and the weather service cautioned the public to “avoid activities that could spark a fire” and warned of the risks associated with high winds, including power outages and damaged or toppled trees or power lines.
— City News Service
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