Though a red flag warning expired Wednesday evening and a high wind warning expired Tuesday, the threat of wildfires will continue Thursday amid low humidity and gusty winds.
NBC 7 meteorologist Dagmar Midcap said conditions will dangerous through Friday afternoon. Until then, Santa Ana winds will continue to whip the county and humidity will stay between 5 and 15 percent in the mountains and deserts.
Midcap said humidity would return to seasonal levels on Friday.
The combination of low humidity, gusty winds and hot temperatures creates the potential for wildfires to spark and spread rapidly.
"Even though the red flag warning expired and the high wind warning expired [Tuesday], conditions remain at borderline critical fire weather condition status," Midcap said.
The San Diego Fire Department said a catalytic converter was to blame for two spot fires Tuesday and Wednesday in the same spot along Los Penasquitos Canyon in Carmel Valley.
Several small spot fires ignited across the county Tuesday but firefighters aggressively tackled each wildfire, sending twice the average crew size, and had the fires out quickly.
Crews have been on alert since the beginning of the Santa Ana conditions last week and several agencies, including San Diego Fire-Rescue, have increased staffing levels as a result.
San Diego Gas & Electric cut power to customers throughout the county Tuesday as a precaution due to the severe wind conditions and restored service in some areas since.
"We are not out of the woods yet," the utility's Twitter account informed customers on Wednesday. "Our meteorology team anticipates winds of 30-45 mph, with isolated gusts of 50-60 mph this morning."
Among the areas where power was turned off as a precaution were Escondido, Rancho Bernardo, San Pasqual, Ranco Penasquitos, Del Dios, Lake Hodges, Harmony Grove, Lake Wohlford, Warner Springs, Ranchita, Palomar Mountain, Lake Henshaw, Oak Grove, Santa Ysabel, Pine Hills, Wynola, North Ramona, La Jolla Indian Reservation, Dulzura, Potrero, Campo, Otay Lake, Otay Mesa, Buckman Springs, Japatul Valley, Morena Village, Pine Valley, Mount Laguna, Jamul and Julian.
All were expected to be without power at least until the red flag warning period ended, the utility company said.
To aid residents with large wildstock, SDG&E secured four water trucks for each of four community resource centers in Julian, Dulzura, Descanso and Mountain Empire on Wednesday, though noted that the water tanks would not arrive until Thursday morning.
Two more resource centers were located in Campo and a second in Julian. All six centers served as places where residents can go to get water and snacks, charge their phones, and get up-to-date information on power outages.
SDG&E also dispatched a large, one megawatt generated to the Julian community to help serve the businesses in the downtown area, said Brian D’Agostino, Director of Fire Science and Climate Adaptation with SDG&E.
Several San Diego County school districts were keeping students at home Tuesday and Wednesday in response to the utility's power shutoff, but by Thursday only on district, Spencer Valley School District, remained closed.
Winds overnight Wednesday were drastically lower than the night before. The highest gusts recorded from 5 a.m. Tuesday to 5 a.m. Wednesday was a gust of 86 miles per hour at Sill Hill (south of Julian).
The inland valleys were being thrashed as well. Alpine saw gusts at 71 mph during that period and Dulzura and Ramona were seeing winds in the low 50s.
Along the coast, Brown Field saw winds speeds at 54 mph and Carlsbad Airport wind gusts topped 38 mph. Solana Beach saw gusts at 35 mph.
Meteorologist Sheena Parveen said Santa Ana conditions would continue through the work week. Some relief would come over the weekend as Santa Ana winds die down and humidity returns.
Warnings are also in effect in the Los Angeles-area where gusty winds could spread the massive 93,000-acre Woolsey Fire that forced about 75,000 people to evacuate.
Read details about the red flag warning here.