Wind advisory with low humidity create critical fire weather in San Diego County
A wind advisory has been issued for San Diego County's valley and mountain areas through 8 p.m. Tuesday, with gusts expected to reach up to 55 mph, the National Weather Service said Monday.
Santa Ana winds were slightly weaker in San Diego County this weekend than in neighboring Orange and Riverside counties, where utilities were considering Public Safety Power Shutoffs in some areas to avoid wildfire danger.
San Diego Gas & Electric has activated its Emergency Operations Center. The utility company said Public Safety Power Shutoffs could happen if conditions worsen.
Local winds were expected to increase Sunday night and remain strong Monday and Tuesday, then weaken by midweek. Dry conditions were expected to accompany offshore winds, according to the NWS.
The strong winds and very low relative humidity (5%-15% across inland areas) will lead to near-critical to critical fire weather conditions through Wednesday, the NWS said.
That's what worries Cal Fire Capt. Brent Pascua. All the brush that sprouted after the winter storms can dry up quickly and become fuel for wildfires.
"What concerns us is how easily the fire starts," he said. And once it starts, wind becomes a major concern.
“It spreads a lot faster, because of the wind," Pascua said. "And then if you add slope from a hill to that, you get a fast, fast-moving brush fire.”
That’s what happened in the Cedar Fire 20 years ago. The wind caused the fire to spread rapidly. But the brush isn’t as dried now as it was then. National Weather Service meteorologist Samantha Connolly said that’s thanks to a couple of weather events this year.
“Because we had a pretty wet winter and we had Tropical Storm Hilary, the fuels have not dried out as much as they usually have for this time of year," she said. "And because it is our first day in a wind event, those fuels have not really gotten a chance to dry out all that much.”
The desert wind will cause warming west of the mountains through Monday, with gradual warming across Southern California by mid-week.
Along the coast, mostly sunny conditions are expected through Friday, with high temperatures hitting the mid-70s. Inland valley areas are expected to be clear and sunny through Friday, with highs reaching the low 80s.
Downtown San Diego on Monday and Tuesday is expected to be sunny, with highs in the low 80s.
San Diego County desert areas were expected to see highs in the 80s throughout the week, with temperatures ranging from 63 to 73 degrees in the mountains.
Monday's San Diego surf forecast expects a moderate-risk rip current, with surf height from 2 to 4 feet, sets to 5 feet in the afternoon, mixed northwest swell from 320 degrees and southwest swell from 220 degrees, and water temperatures from 62 to 66 degrees.