Powerful Santa Ana winds gave San Diego County's humidity levels little chance to recover overnight Tuesday as the National Weather Service extended a red flag warning for another day.
A small spot fire broke out in Santee just after noon but was quickly extinguished by fire crews who have been on alert since the beginning of the Santa Ana conditions last week. Santee firefighters said the fire at Hartley Road and N. Woodside Avenue burned less than an acre.
Shortly after, there was a small vegetation fire on E. Mission Road in Fallbrook that briefly threatened structures before firefighters were able to get a handle on it.
Already-low humidity was expected to drop to critical levels that when combined with gusty winds have the potential to spread quickly and dangerously with any fire spark, NBC 7's Meteorologist Sheena Parveen said.
"It's another day where we have some very dangerous Santa Ana winds," Parveen said. "Do not burn anything. Don’t use anything that can cause a spark because that could easily ignite some fires across the area."
Meanwhile, the red flag warning in effect from San Diego's mountains to the coast was extended until 5 p.m. Wednesday.
NBC 7 meteorologist Dagmar Midcap said though the wind warning expired Tuesday evening, the county would still be experiencing potentially dangerous Santa Ana wind patterns that would bring about dry conditions.
San Diego Gas & Electric cut power to even more customers on Tuesday as a precaution due to the severe wind conditions, bringing the total number of homes and businesses that could be with electricity to more than 24,000, according to the utility company.
Strong winds had knocked out power to an additional 7,300 customers.
San Marcos, Escondido, Encinitas, Rancho Santa Fe, Rancho Penasquitos and Rancho Bernardo were some of the areas who may have had their power shut off Tuesday morning.
SDG&E may have also cut power to customers in Warner Springs, Dulzura, Potrero, Campo, Jamul, Lyons Valley, Barrett Lake, Dehesa, Alpine, Japatul Valley, Buckman Springs, Morena Village, Otay Lake, Otay Mesa, Viejas, Boulder Creek, Pine Valley, Mount Laguna, Valley Center, Pauma Valley, Santa Ysabel, Lake Henshaw, Ramona, San Diego Country Estates, Wynola, Live Oak Springs, Boulevard, and Julian/Kentwood in the Pines.
SDG&E 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 are keeping students at home Wednesday in response to the utility's power shutoff.
D’Agostino said the agency is using 177 weather stations to closely monitor the winds, which he described as "hurricane-force."
Persistent winds averaged 60 miles per hour in the mountains and in the 40s for the inland valleys overnight. Even coastal areas like Del Mar were experiencing 25 mph wind gusts, Parveen said.
The strongest gusts recorded overnight were at Sill Hill (south of Julian) and Boulder Creek (west of Lake Cuyamaca) at 86 and 69 mph respectively, according to the NWS. Descanso, Boulevard and Campo saw winds in the mid-50s.
Winds would become more widespread at sunrise and be strongest through the afternoon, the NWS said.
NBC 7 Meteorologist Dagmar Midcap said the county was experiencing something called a Mountain Wave, which involves wind interacting with a layer of warm air above a cooler surface layer, making the wind stronger and more erratic.
Midcap said those erratic winds should be expected into at least Tuesday afternoon.
Residents in fire-scarred Alpine, where a devastating vegetation fire tore through the foothill community of Alpine on July 5, were prepping for the fire weather conditions on Monday.
"Anytime there’s winds now we are definitely more on alert than we were before the fire we had," said Aaron Silver, whose home survived the West Fire.
The red flag warning is in effect until 5 p.m. Wednesday but Parveen said Santa Ana conditions would continue through the work week.
"Those very high winds, gusts over 70, that’s what’s really expiring. We’re still going to windy conditions so don’t think the winds are going to die down tremendously when this expires."
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.