By Hailey Branson-Potts and Melissa Etehad

Los Angeles Times

LOS ANGELES — Weaker winds, cooler temperatures and higher humidity early this week should help firefighters battling the massive Thomas fire in Santa Barbara and Ventura counties, forecasters said.

The 270,500-acre fire has been driven by seemingly nonstop winds and bone-dry conditions over the past two weeks. By midmorning Monday, winds throughout the region are expected to diminish, and weather conditions are looking relatively tranquil through Wednesday afternoon, said Dave Bruno, a meteorologist with the National Weather Service in Oxnard.

“They’ll have a few good days to work on it,” Bruno said of firefighters battling the conflagration. “It’s one of the longest respites we’ve had. It’s been pretty relentless since the second of December.”

On Sunday morning, wind gusts topped 70 mph in mountain areas in the fire zone and 50 mph on the Ventura County coast. But they calmed as the day wore on, allowing fire crews to mop up hot spots and remove dry vegetation by the homes they’d saved in Montecito.

Weak northeast winds prevailed across the fire Sunday night and were expected to shift to a south to southwest direction by Monday afternoon, according to the California Department of Forestry and Fire Protection. Slower gusts and cooler temperatures would allow for “favorable firefighting efforts,” fire officials said.

Cool onshore winds will help the fire back up on itself, said Antonio Negrete, a Cal Fire spokesman.

Areas of concern for firefighters include the coastal communities of Santa Barbara, Summerland and Montecito, as well as the Matilija Wilderness and Rose Valley, according to Cal Fire. On the eastern side of the fire, the threat continues for Fillmore in Ventura County.

Fire crews on Monday are expected to focus on Fillmore. Fire activity has decreased in that area, but firefighters want to use the favorable wind conditions to their advantage there, Negrete said. Crews will try to protect homes and avocado ranches there and will have support from water-dropping helicopters.

In the Santa Barbara County towns of Montecito and Summerland, firefighters will continue mop-up efforts to prevent flare-ups, Negrete said.

The air is expected to remain dry on Monday, but a more extensive onshore flow Tuesday is expected to increase humidity levels along the coast, according to the weather service.

The respite, however, will be brief, Bruno said.

A weak upper-level low-pressure system is expected to move through the region on Wednesday, bringing gusty winds behind it, Bruno said.

“Once the front moves through, strong northwest to north winds will develop across Santa Barbara County late Wednesday afternoon and night,” Bruno said. “Those winds will transition to more typical Santa Ana winds that would affect L.A. and Ventura counties on Thursday.”

The system could bring some minor showers to Santa Barbara and San Luis Obispo counties, but “nothing that will help the fire in the least,” Bruno said.

“It’ll just be a few sprinkles, some spitting,” he said. “Firefighters will be much better served by the cooler weather beforehand.”

There is no other rain in sight through at least Christmas, thanks to a persistent high-pressure system over the western U.S., Bruno said.

“It is abnormal,” he said. “Normally, we start getting rain on a regular basis by November. We usually get a good storm by now. This is kind of ridiculous.”

The Thomas fire as of Monday morning was 45 percent contained, according to Cal Fire. It has destroyed 1,024 structures and damaged 250 more.

An additional 18,000 structures remain threatened. The cost to fight the fire so far has exceeded $130 million, authorities said Monday.