REGION — A red flag fire warning triggered by Santa Ana winds for much of San Diego County as a wildfire driven by conditions sifting through Ventura County north of Los Angeles and low humidity levels stayed in effect now.
A high wind warning also stayed in effect now, with all the red flag warning set to expire late Thursday night and the high wind warning anticipated to expire Thursday afternoon, according to the National Weather Service. But the Santa Ana winds could persist into Friday or Saturday, which will mean an extension of the two warnings.
The red flag warning was issued by the NWS for the San Diego County region, inland valleys and mountains, including Descanso Ranger Districts of the Cleveland National Forest and also the Palomar.
Today and Wednesday, sustained winds are anticipated to be between 20 and 30 mph with gusts around 55 or 60 mph, the NWS said. But forecasters now consider Thursday and Friday pose the most important fire risks Thursday.
Helping this week to mitigate the fire danger are the weather. High temperatures now in San Diego County will be 70 to 75 degrees at 48 to 58 from the mountains, 61 to 66 near the foothills and the beaches, inland and in the western valleys.
The fire threat this week doesn’t come from high temperatures. On the contrary, it’s humidity amounts and the strong winds anticipated to be in the 5 to 15 percent range from Wednesday and the 7 to 15 percent range now .
The wildfire threat was on full screen this morning in Ventura County, where the “Thomas Fire” was being driven by Santa Ana winds and conditions similar to neighborhood problems. That blaze erupted around 6:30 p.m. Monday and immediately spread, rising to 31,000 acres and destroying at least 150 structures as of 3:45 a.m. today.
Both the San Diego Fire-Rescue Department and San Diego Gas & Electric beefed up staffing levels, to prepare for the conditions. The fire department put several strike teams on alert that comprised two water tenders, five engines, 10 brush replacements and two helicopters. SDG&E officials staged contract firefighters and subject crews where winds are predicted to be the most powerful.
“Meteorologists at the National Weather Service haven’t seen models to get a Santa Ana event similar to this in several years,” SDFD Chief Brian Fennessy said. “We are being vigilant in up-staffing to safeguard San Diegans and their land. We ask that residents practice their evacuation strategies and also be prepared in the event of a wildfire.”
SDG&E — which last week lost a ruling in connection to the 2007 wildfires the business was found responsible for beginning — said it may need to turn off power this week in certain areas “if weather conditions threaten the integrity of our system and make the prospect of an imminent emergency.”
Fire officials said fire fuel was generated by several years of drought last winter, coupled with heavy rains . But the lack of rain and low humidity levels have dried out the fuel.
The U.S. Forest Service’s Santa Ana Wildfire Threat Index, which categorizes Santa Ana winds based on anticipated fire potential too extreme, high, moderate, marginal or no evaluation, predicts that Thursday the threat index will probably be extreme and Friday it will be high. While Wednesday and Saturday were recorded as moderate nowadays, the index recorded the danger marginal.
On Thursday, with gusts possibly exceeding 80 mph, the Forest Service explained that “upon railway, fires will have extreme expansion, will burn very intensely, and will probably be uncontrollable.”
SDFD officials and the NWS warned residents to “prevent activities that could ignite a fire” and warned of the dangers of high winds which include things like power outages and damaged or toppled trees or power lines.