The Santa Ana winds that led San Diego Gas & Electric to shut off power to more than 5,900 customers on Tuesday are now reaching their peak and come amid dangerously low relative humidity across critically dry San Diego County, the National Weather Service says.
Wednesday’s pre-dawn winds reached 74 mph at Sill Hill in the Cuyamaca Mountains, 53 mph in Alpine, 40 mph at Ramona, 33 mph at Montgomery Field and Brown Field, and 31 mph at Marine Corps Air Station Miramar. The relative humidity ranges from 9% inland to 15% at the coast.
The gusts also follow a night of unusually cold weather. The pre-dawn temperature hit 38 degrees at Camp Pendleton, 39 in Oceanside and 39 in San Diego. The winds have been drawing energy from Canada.
Forecasters say the winds might be followed by another major Santa Ana wind event next Monday and possibly one next Thursday, the weather service said.
Wednesday’s winds have not led to a major jump in the number of SDGE customers who’ve lost power, but further disruptions remain possible.
Forecasters said the winds could show special force in and around Marine Corps Air Station Miramar, which sits near the mouth of a corridor that funnels winds from the desert toward the sea. The same is true of Camp Pendleton in North County.
The latest windstorm comes during a period of dryness that hasn’t been experienced by anyone alive today. San Diego International Airport has recorded only 0.14 inches of precipitation since October — the driest start to the rainy season since 1850, when record-keeping began locally.
“The vegetation is starving for moisture,” said Alex Tardy, a weather service forecaster.
There’s no significant rain in the forecast through Jan. 28.
High-pressure systems have been preventing storms from the Gulf of Alaska from sinking deep into Southern California.
“I don’t see any pattern shift (this month) that would produce winter weather,” said Brian D’Agostino, vice president of wildfire and climate science at SDG&E.
Tuesday’s winds hit 74 mph at Sill Hill, a spot in the Cuyamaca Mountains, and reached 51 mph in Alpine, 40 mph at Ramona Airport and 39 mph on Sunrise Highway in the Laguna Mountains.
There also have been gusts of 28 mph at Camp Pendleton, 20 mph in Carlsbad and 15 mph in Leucadia. Relative humidity across much of the county is in the 9% to 13% range.
Tuesday’s outages came as fire crews knocked down a small brush fire in Ramona that ignited early Tuesday and briefly threatened a home.
The fire was reported shortly after 6:30 a.m. near Pamo Road and Haverford Road. Cal Fire Capt. Robert Johnson said no structures were damaged, and there were no reports of injuries.
Fire officials initially reported the blaze had charred around 10 acres, but Johnson said it likely was around 5 acres. Two fire investigators were trying to determine what sparked the blaze, Johnson said.
On Monday, a wildfire burned 12 acres at Marine Corps Air Station Miramar before it was put out.
