A Fire Weather Watch, indicating that conditions conducive to wildfire may develop, will be in effect in the mountains and valleys of San Diego County from tomorrow night through Saturday evening, the National Weather Service said today.
The NWS said it was issuing the Fire Weather Watch because humidity levels are expected to be low and gusty winds are expected to develop, although they will not be as severe as those that churned up the wildfires that began last month.
"High pressure will develop in the Great Basin and bring low humidities to the area and locally gusty winds through and below mountain passes and canyons," according to an NWS advisory.
The winds, which will develop Friday night, will blow at strengths of between 15 and 25 miles per hour, "with very isolated gusts to near 40 miles per hour," the advisory said. It said the winds would be at their strongest between 6 a.m. and noon Saturday, decreasing as the day wears on.
Of even greater concern was the prospect of dry conditions.
"Relative humidities will decrease to around 10 percent before noon Saturday and could remain at those levels for up to 10 hours," the advisory said, adding that the Fire Weather Watch was being issued "mainly" because of the low-humidity forecast.
In San Diego County, the Fire Weather Watch will be in force in the inland valleys and the Palomar and Descanso Ranger Districts of the Cleveland National Forest in the Santa Ana Mountains.
A Fire Weather Watch will also be in effect in the mountains and valleys of Riverside and San Bernardino counties.
The NWS said it is possible that the Fire Weather Watch will be replaced by a more serious Red Flag Warning, which denotes a high risk of wildfire.
Only one of the nine fires that broke out in San Diego County last month has yet to be fully contained. The Poomacha Fire, which broke out Oct. 23 on La Jolla Indian Reservation, is 85 percent contained today after scorching 50,156 acres.
The deadliest of the county's fires, the Harris Fire, was 100 percent contained yesterday morning after claiming five lives and spreading 90,440 acres since it began Oct. 21. The blaze is expected to be under control by Saturday.
Also fully contained yesterday was the Witch fire. The biggest of the county's wildland blazes, it scorched 197,990 acres, destroying 1,125 homes and 499 outbuildings, according to Cal Fire. It's expected to be under full control by Monday.
Citing the expected return of offshore winds, Gov. Arnold Schwarzenegger yesterday directed state agencies and the National Guard to be prepared for a possible new round of blazes.
"We're not out of the danger zone yet," he said at a news conference following a meeting in downtown Los Angeles with the California Association of Governments to discuss the state's response to the wildfires that began swallowing acreage and homes on Oct. 20.
"We are watching the weather very closely ...," Schwarzenegger said.
The governor said there are aircraft in place if the winds pick up Friday night as expected, and emergency staff have been pre-positioned in areas with a high risk of fire.
