Ask firefighters what contributes to most of Southern California’s big wildfires, and you will probably hear a simple formula: tinder-dry brush and grass, plus Santa Ana winds and a spark at just the wrong place.
Dry brush and strong winds are status quo for Southern California this time of year, and current conditions are adding up to the usual pattern.
Although rains drenched Ventura County last winter, the brush has dried out in the ensuing seven months. And the conditions that create the dry, sometimes hot winds known as Santa Anas are brewing, authorities said.
Santa Anas typically begin to develop in October, when high-pressure zones in the Great Basin drive winds over the Sierra Nevada, through passes and canyons, and down to the coast.
Forecasters predict that the first warm winds of the season will blow into the county this weekend and the beginning of next week when a high-pressure zone moves off the Central Coast to the Great Basin, said Stuart Seto, a weather specialist for the National Weather Service in Oxnard.
Winds of up to 30 mph from the northeast are expected in much of Ventura County beginning Sunday and continuing through early Tuesday, Seto said. During the same period, temperatures are expected to climb into the 80s in Oxnard and Thousand Oaks. Temperatures in the 90s are expected in Ojai by Tuesday.
“It looks like it’s going to be one of the first Santa Ana events” this season, Seto said.
The National Weather Service also is issuing a red-flag warning this weekend. The warnings are issued when conditions are ideal for wildland fires.
The Forest Service is bolstering its firefighting forces in Southern California in preparation for the high winds this weekend, officials said late Thursday. In Los Padres National Forest, five more fire engines will be positioned between the Ojai Ranger District and the Santa Barbara Ranger District; one hand crew will be staged in the Santa Barbara District; one hand crew will be staged in the Mt. Pinos Ranger District; an additional helicopter will be assigned to the Ojai District; and two airtankers will be positioned at the Santa Maria Air Attack Base, according to Forest Service officials.
Ventura County currently has some of the same conditions that led to the devastating fires that swept through the state last year and to the Shekell fire the year before, in Moorpark.
Although rainfall totals were nearly normal last winter, most local areas have gotten less than 0.2 of an inch of rain since February. Brush in much of the county is already critically dry, and moisture levels in plants are slightly below normal in Simi Valley and Malibu, said Capt. Brendan Ripley, a fire behavior specialist for the Ventura County Fire Department.
Chaparral is even drier than it was before the catastrophic fire season of 2007, said Capt. Drew Smith, a fire behavior analyst for the Los Angeles County Fire Department.
“This is historically when we get our largest fires,” he said. “The recipe is there right now for large fire development when faced with forecasted Santa Ana events.”
High winds can push fires quickly across dry brush and grass, tossing out embers that can spark spot fires, Ripley said. “It’s our enemy,” he said.
When Santa Anas blow into the region, even moisture built up from above-average rainfall can’t always protect plants, said Scott Holder, hydrologist for the Ventura County Watershed Protection District. “In 2005, we had the Day fire after that record winter,” he said.
Santa Anas drain moisture from plants in much the same way they dry out skin, Holder said.
Story by Ventura County Star
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