Latest Kincade Fire news: Containment drops to 5% after intense winds on Sunday

— 54,298 acres, 5% containment, down from 10% earlier Sunday

— At least 91 structures destroyed, 17 damaged

— No reported deaths or missing persons

— 80,000 structures threatened

LATEST: October 27, 6:50 p.m.: Containment drops after rough day on fire lines

Containment of the massive Kincade Fire has dropped down to 5% due to vicious winds on the fire lines throughout Sunday.

The morning began with 10% containment of the blaze, but gusts of over 100 miles per hour helped spread the flames rapidly.

"We're continuing to see the erratic fire spread," said fire behavior analyst Steve Volmer at a Cal Fire press conference late Sunday.

The fire has reached the edge of the town of Windsor, but Cal Fire authorities said the fire line was holding steady there for now. A weakening of Sunday's hurricane-force winds should help with the fight.

"It looks like we have about a 24-hour window of favorable weather Monday into Tuesday," National Weather Service meteorologist Mark Walbrun said.

Unfortunately, another wind event is in the forecast for Tuesday, and there's no rain in sight through the end of the month.

No additional evacuation orders have been issued since early Sunday afternoon, although evacuees are also not yet permitted to return to their homes. Sonoma County Sheriff Mark Essick said one "unauthorized" person was found in an evacuated neighborhood by police and arrested for reentry into an unauthorized area. Essick said the individual could not prove they were a resident in the neighborhood.

CHP said they will reopen southbound Highway 101 shortly, but northbound lanes will continue to remain closed indefinitely.

UPDATE: October 27, 1:30 p.m.: More evacuations issued

Napa County's Office of Emergency Services issued an advisory evacuation order Sunday afternoon for the greater Calistoga area because of the erratic behavior of the Kincade Fire in Sonoma County. (Find a map here.)

County officials are asking residents in the city of Calistoga and the following surrounding coordinates to prepare for possible evacuation:

-North of Diamond Mountain Road to Dunaweal Lane

-East of Sonoma County Line

-South of Lake County Line

-West of Pickett Road

The advisory includes Oat Hill Road and Livermore Road at the Napa and Lake County line.

This is the first evacuation issued for Napa County. Some 200,000 people in Sonoma County remained under evacuation orders, including Geyserville, Windsor, Headsburg and portions of Santa Rosa.

Find Sonoma County evacuation information here.

Find Napa County evacuation information here.

UPDATE: October 27, 11:20 a.m.: Residents of Milk Barn Road area told to leave immediately

The Sonoma County Sheriff tweeted, "If you are in the area between Windsor and Healdsburg near Milk Barn Rd and Limerick Ln EVACUATE NOW. Firefighters are engaged in spot fires in the Milk Barn Rd area, Limerick Ln area, Hillview Ln. and Arata Ln area. If you have not evacuated, you NEED to do so now!"

Calistoga isn't under evacuation at this time, according to the Napa County Sheriff department. "It would be premature to go with that information at this point," said Henry Wofford, the PIO for the sheriff Department. "I wouldn't say anything is official in any town in Napa County unless you have seen it through a Nixle alert. It would be sent through our Office of Emergency of Services. But things can change very rapidly." Woffer said the Napa County Sheriff department Facebook and Twitter accounts are sources for evacuation information.

UPDATE: October 27, 10:30 a.m.: Portion of Highway 101 closes again, more evacuations under consideration

In a 10 a.m. news conference, Cal Fire officials said a primary focus today is preventing the Kincade Fire from spreading west across Highway 101 into an area that's dense with foliage and hasn't burned since the 1940s.

"Last night we saw an increase in fire behavior due to winds that came through, and those winds pushed that fire down into the Highway 126 corridor and into those communities," said Steve Volmer, a fire behavior analyst with Cal Fire. "We have spotting potential up to and over one mile, and we have rates of spread that are extremely dangerous and erratic."

Volmer said the new fires that start from embers being blown by winds are especially problematic because they can have the same rates of spread as the main blaze. "If anything does start on the opposite side of 101, the west side, that area hasn't seen any fire history since the 1940s," he said. "Those fuels in that area are extremely dense and dry."

More updates include the re-closure of Highway 101 from Arata to Dry Creek due to low visibility from wildfire smoke. Cal Fire said the target date for full containment is Nov. 7. Evacuations in some parts of Napa County are under consideration but haven't been finalized.

More than 180,000 people are under mandatory evacuation and the Sonoma County Sheriff department said it's possibly the largest such evacuation in history.

Sheriff Mark Essick said he has heard concerns the evacuations are overkill. "I think those concerns are not valid," he said. "We're encouraging people to get out."

National Weather Service meteorologist Mark Walbrun said severe critical fire weather persists in the area of the fire Sunday morning. "Humidity values went into the single digits which is dangerously low for fire spread," Walbrun said. "Last night on the fire lines itself, we had reported wind gusts of 76 mph. A Red Flag Warning continues through 11 a.m. Monday."

For the most up-to-date information on evacuations, visit the Sonoma County Emergency website.

Find evacuation and road closure information, here.

UPDATE: October 27, 5:30 a.m.: The Kincade Fire has swallowed 30,000 acres

The most severe wind event the North Bay has seen since 2017 whipped the raging Kincade Fire in north Sonoma County Sunday morning, leading to mass evacuations.

Cal Fire officials said Sunday morning the fire has consumed more than 30,000 acres since the blaze started Wednesday night. The containment has gone down from 11% to 10%. No injuries or deaths have been reported. So far 79 structures (31 of those homes) have been destroyed and 31,175 structures are threatened.

"The North side of the fire is burning in remote, steep terrain while southern portions of the fire have begun to impact the southern Alexander Valley," Cal Fire reported.

Sonoma County Emergency released an alert before sunrise saying the fire is approaching the town of Healdsburg. "Fire heading toward city," the alert read. "Leave now."

At 9:30 a.m., Healdsburg Mayor David Hagele told KTVU-TV that while fires are around the city, "As of now we are protected. The recommendation was to evacuate so people could do their jobs and fight the fire rather than have to focus on evacuating people."

Approximately 180,000 people are under an evacuation order, and the Sonoma County Sheriff department said, "This is the largest evacuation that any of us at the Sheriff’s Office can remember. Take care of each other."

Mandatory evacuations are now in place in the following areas in 10 zones: zone 1: Geyserville; zone 2: Knights Valley; zone 3: Healdsburg and Windsor; zone 4: Dry Creek Valley; zone 5: Mark West, Larkfield, Wikiup; zone 6: NE Santa Rosa including Fountaingrove, Oakmont, Rincon Valley; zone 7: Forestville, Guerneville, Duncans Mills, Jenner, Bodega Bay, Occidenta; zone 8: Sebastopol and Valley Ford; zone 9: Coffey Park and Santa Rosa north of Guerneville Rd-Steele Lane and zone 10: West of Stony Point Road between Guerneville Rd. and Ludwig Ave.

At a news conference Sunday, Sheriff Mark Essick said he has heard concerns the evacuations are overkill. "I think those concerns are not valid," he said. "We're encouraging people to get out."

For the most up-to-date information on evacuations, visit the Sonoma County Emergency website.

Highway 101 is closed from Arata to Dry Creek

Highway 101 was closed entirely northbound at Hopper Avenue in Santa Rosa and southbound at Cloverdale Blvd South in Cloverdale before sunrise. At 7 a.m. the Sonoma County Sheriff said in an alert, "At this time Hwy 101 between Santa Rosa and Cloverdale is in the process of being reopened to through traffic."

In Santa Rosa, the Kaiser Hospital and the Sutter Regional Hospital were evacuated. The North County Detention Facility was also evacuated and inmates were taken to Alameda County.

The Kincade Fire was reported Wednesday at 9:27 p.m near Geyserville. Amid wind conditions overnight Saturday and into Sunday morning, the fire is spreading with gusts throwing embers and starting spot fires.

"The fire started spotting and has crossed Highway 128 in the Soda Rock Area," Cal Fire spokesperson Scott McLean told KTVU-TV.

Forecasters say the wind picked up as expected late Saturday and the most extreme gusts are forecast to develop between 5 a.m. and 8 a.m.

"The winds have definitely developed like expected," said Spencer Tangen, a forecaster with the National Weather Service office in Monterey. "This has been an extreme wind event and on par with 2017."

Spencer says the highest speed recorded so far was an 87 mph gust atop Mount St. Helena. Sustained gusts of 30 to 50 mph are being observed in the valley areas of Santa Rosa.

"The winds won't subside until Monday morning," said Tangen. "There will be gusts the whole day. The wind gusts up in the hills won't be quite as bad this afternoon, but then they'll pick up this evening. I don't think the winds early Monday morning will be as bad as they are this morning."

More Kincade Fire coverage:

— Kincade Fire containment drops to 5% after brutal day on fire lines

—102 mph gust recorded in Sonoma County: Sustained winds break hurricane force

— Tuesday wind event will trigger even more PG&E power shut-offs

— Maps: Kincade Fire burning in north Sonoma County

—Road closures, evacuation shelter locations near Kincade Fire

—What to do to keep wildfire smoke out of your house

— Full California wildfire coverage

Amy Graff is a digital editor at SFGATE. Email her at agraff@sfgate.com.