Santa Ana winds driving six major wildfires in Southern California — including the 4,100-acre Lilac Fire burning near Fallbrook and Oceanside — are expected to weaken Friday before strengthening again over the weekend.
Much of San Diego County will remain under a red flag wildfire warning Friday that the National Weather Service extended until 8 p.m. Sunday. A high wind warning was set to expire at 4 p.m. Friday.
Santa Ana winds were strong and gusty Thursday, driving flames from the Lilac Fire east to west from Interstate 15 toward the coast with gusts reaching about 60 mph in the North County. A gust of 88 mph was recorded Thursday at Sill Hill near Julian.
Winds are expected to be 15 to 25 mph Friday morning with gusts of up to 40 mph before weakening throughout the day.
Firefighters hope the calmer winds will provide better conditions to battle the Lilac Fire, which erupted for unknown reasons about 11:25 a.m. Thursday just west of Interstate 15 and north of Lilac Road in Pala Mesa amid gusty, arid weather. By 8 p.m., the last time authorities updated the size of the blaze, flames had scorched 4,100 acres and crews had gained no containment on the fire.
But an onshore breeze could complicate firefighting conditions this afternoon, the weather service said.
“An onshore sea breeze will move in … across the inland valleys in the afternoon, impacted (by) the Lilac and Liberty Fires,” the NWS said, referencing a second fire burning in Riverside County northeast of Murrieta. “The winds will range from 8 to 16 mph, and may result in erratic fire behavior during the time of the wind shift.”
Any reprieve provided by the weakening Santa Ana winds will also be short-lived as those winds will strengthen Saturday to 20 to 30 mph with gusts exceeding 50 mph. Forecasters predict 20 to 35 mph winds Sunday with gusts exceeding 55 mph.
Near-negligible humidity levels hovering around 5 percent will also continue throughout the weekend, with the arid conditions and parched vegetation adding to the danger caused by the winds. The only slightly mitigating factor is the temperature outlook, though a warming trend is underway and temperatures are expected to be well above average throughout the weekend.
High temperatures Friday will be 75 to 80 degrees at the beaches, 78 to 83 inland, 80 in the western valleys, 72 to 77 near the foothills and 59 to 69 in the mountains.
The U.S. Forest Service‘s Santa Ana Wildfire Threat Index, which categorizes Santa Ana winds based on anticipated fire potential as extreme, high, moderate, marginal or no rating, predicts a marginal threat for Friday, a moderate threat Saturday and a high threat Sunday. Thursday, when the Lilac Fire broke out, the threat was extreme.
Under the conditions expected Friday, any new fires “may grow rapidly,” the Forest Service said. Under Saturday’s moderate threat conditions, any new fires “will grow rapidly and will be difficult to control.” Under Sunday’s high threat conditions, any new fires “will grow very rapidly, will burn intensely, and will be very difficult to control.”
The weather service urged residents to “avoid activities that could spark a fire” and warned of the dangers of high winds, including power outages and damaged or toppled trees or power lines.
— City News Service
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