Heat expected to complicate crews’ fight to contain wildfires
Fire crews embarking on their third week of trying to contain a series of wildfires in the region heard three words from weather forecasters Monday morning that only added to their challenge:
High pressure buildup. “Yeah,” meteorologist Matt Mehle of the National Weather Service said. “It’s going to bring another round of excessive heat by the weekend.”
Firefighters on Monday still felt some coolness from a thick marine layer and continued to make progress on the SCU, LNU and CZU Lightning Complex fires. Those fires, burning in portions of Santa Clara, Alameda, Contra Costa, Santa Cruz, San Mateo, Napa, Solano, San Joaquin, Stanislaus, Merced, Lake and Yolo counties, had consumed a combined 843,006 acres, or 1,317 square miles, through Monday morning, according to the California Department of Fire and Forestry.
In all, the fires have been responsible for six deaths and 10 injuries, Cal Fire officials said.
The CZU Lightning Complex fires in San Mateo and Santa Cruz counties had destroyed 1,361 buildings and damaged 132 more, making it the most destructive of the three fires. That blaze had burned 84,640 acres and was 39% contained as of Monday morning.
The LNU Complex fires in Napa, Solano, Sonoma, Yolo and Lake counties have destroyed 1,209 buildings and damaged 193 others, scorching some 375,209 acres and reaching 63% containment on Monday morning.
The SCU Lightning fires in Santa Clara, Alameda, Contra Costa, Stainslaus, San Joaquin, Stanislaus, and Merced counties have destroyed 40 buildings and damaged 18 others. That complex has burned some 383,157 acres and was 60% contained on Monday.
The fight is expected to become tougher this week, as an increase in barometric pressure and the atmospheric bubble that will develop are expected by the weekend to crank up the temperatures to levels approaching the heat wave in late August, Mehle said.
The compression of the marine layer by the high pressure also will create a ceiling that will continue to trap the smoke and other pollutants. A Spare the Air alert issued by the Bay Area Air Quality Management District on Aug. 17 has now been extended through tonight.
“We don’t have a lot of mixing occurring in the atmosphere the next few days,” Mehle said. “So as high pressure builds, it will be like a giant lid on the atmosphere. We’ll be holding onto this smoke and haze for some time.”
By noon Monday, the air quality was the worst in Napa, where the official reading of fine particulate matter was 142, considered unhealthy for those with breathing problems or other underlying conditions. The readings were lower in San Francisco (121), Redwood City (114) Laney College in Oakland (109), West Oakland (108), East Oakland (102) and Berkeley (101). The official air readings fell into the moderate category (50100) in Concord, LIvermore, Pleasanton and San Jose. Official air readings out of Santa Cruz County also showed the air there to be good.
All evacuation orders were changed to warnings in Santa Clara County and all evacuation notices that already were warnings were lifted altogether, according to Cal Fire. All evacuation orders were lifted in the San Joaquin County for the SCU Lightning fire Monday morning.
In Boulder Creek, near the CZU Lightning fires, resident Chucke Walkden said Monday he had been driving around the fire-ravaged neighborhoods feeding and watering whatever animals they could find, most left behind by their fleeing owners. Walkden said he’s “just trying to keep them alive until people can get back home.”
Walkden said he has been receiving help from his wife, Wilhelmina Ribicki, who has been coordinating his operation via social media, as well as local residents Josh and Andy McHone.
“I have a list of about 75 to 100 houses,” Walkden said. “There’s a cat here, two cats there, three cats. there’s been three little pigs. Chickens. Some ducks. I’m looking for two dogs. We found one. We’ve got cat food and dog food and bird food. I find stray animals along the way.”
He said when the owners return, the animals may be a little hungry, “but they’ll be alive.”
Cal Fire officials at all three fire sites reported reduced humidity at higher levels and said they aimed to work quickly to contain as many areas of the blazes as possible before the next heat wave hit. An increase in humidity that came with a marine layer had helped with some of the heavy, dead brush that has helped to fuel the fires, according to Cal Fire.
That marine layer is about to be compressed by the building barometric pressure, and we will all feel that by the holiday weekend, Mehle said.
“The first real ramp-up of that will be Friday,” he said. “But the real peak heat is going to be Saturday and more so into Sunday. It will be be very similar to the last one.”
Mehle said temperatures will be in triple digits “in many areas” and that the Bay Area’s hottest inland locations such as Livermore, Brentwood and Antioch could get up to 104, “though it’s far too early in the week to really know. We have to see what happens with the high pressure.”