(CNN) In some areas in Sonoma County, the wildfires that have ravaged tens of thousands of acres died down enough Wednesday for the sheriff's department to check on more than 600 missing persons reports by visiting burned-out neighborhoods.

In many other cases, detectives used telephones to track down people who are unaccounted for.

Still, 285 people remain missing in just this one county, people who authorities pray are still alive but have no way to contact police or their loved ones.

But there is some dread that the death toll -- 23 in the region -- from the Northern California wildfires will rise as more areas cool down and searchers discover what's left.

"I'm optimistic that we will get a lot of people connected," Sonoma County Sheriff Rob Giordano said. "At the same time we have to be realistic and start searching for the ones we found are missing."

Firefighters battling 22 blazes were challenged Wednesday by blustery conditions and shifting winds.

Gusts had died down early this week, but on Wednesday they blew between 20 and 40 mph and conditions were still extremely dry, with low humidity and no rain. Thursday's forecast is for similar conditions.

More than 20,000 people had been ordered to evacuate as of Wednesday, and authorities were encouraging others to pack "ready-to-go bags" with documents and medicines in case they had to flee the fast-spreading flames on a moment's notice.

Giordano had a suggestion for people who'd been advised to be prepared to leave: Go anyway.

"Traffic is bad in the county. If we have to evacuate people, it'd be better to have you (already) out of the area. If you have a place to go, go," he said.

"We are very concerned about all the fire lines, because of the wind they're anticipating," he said.

Photos: Wildfires blaze in California Aerial images showing parts of Sonoma and Napa County that have been hit by wildfires. Hide Caption 1 of 33 Photos: Wildfires blaze in California Colby Clark, left, comforts her mother, Bonnie Trexler, after law enforcement escorted them to Trexler's home in Napa, California, to retrieve medicine and personal items on Wednesday, October 11. Trexler was one of the lucky few in her neighborhood whose home was spared. Deadly wildfires have been tearing through the state, destroying homes and businesses and prompting evacuation orders. Hide Caption 2 of 33 Photos: Wildfires blaze in California Highway Patrol officers go door to door to ask Sonoma residents to evacuate their homes as a wildfire approaches on October 11. Hide Caption 3 of 33 Photos: Wildfires blaze in California Homes are destroyed in the Coffey Park neighborhood of Santa Rosa on October 11. Hide Caption 4 of 33 Photos: Wildfires blaze in California The sign of a Firestone store malfunctions in Santa Rosa on Tuesday, October 10. Hide Caption 5 of 33 Photos: Wildfires blaze in California Damaged winemaking vats and tanks stand in ashes and debris at the Paradise Ridge Winery in Santa Rosa. Hide Caption 6 of 33 Photos: Wildfires blaze in California Smoke clouds the sun from wildfires burning in Santa Rosa and Napa Valley on October 10. Hide Caption 7 of 33 Photos: Wildfires blaze in California Mary Caughey, center in blue, reacts after finding her wedding ring in the remains of her home in Kenwood on October 10. Hide Caption 8 of 33 Photos: Wildfires blaze in California Puddles of melted metal trail away from a burned-out car near Napa on October 10. Hide Caption 9 of 33 Photos: Wildfires blaze in California A TV cameraman inches closer to a burning building at a winery in Napa Valley on Monday, October 9. Hide Caption 10 of 33 Photos: Wildfires blaze in California A firefighting plane helps battle a blaze just north of Tustin on October 9. Hide Caption 11 of 33 Photos: Wildfires blaze in California A historic barn burns in Santa Rosa on October 9. Hide Caption 12 of 33 Photos: Wildfires blaze in California The Santa Rosa Hilton Hotel burns to the ground on October 9. Hide Caption 13 of 33 Photos: Wildfires blaze in California Jim Stites watches as part of his neighborhood burns in Fountaingrove on October 9. Hide Caption 14 of 33 Photos: Wildfires blaze in California Fire burns from an open gas valve near the pool area of a Santa Rosa trailer park on October 9. Hide Caption 15 of 33 Photos: Wildfires blaze in California A man rushes to save his house as a wildfire moves through Glen Ellen on October 9. Hide Caption 16 of 33 Photos: Wildfires blaze in California Kristine Pond searches what's left of her family's home in Santa Rosa on October 9. Hide Caption 17 of 33 Photos: Wildfires blaze in California Police cars block State Route 241 as smoke rises above Orange on October 9. Hide Caption 18 of 33 Photos: Wildfires blaze in California A firefighter douses flames in Santa Rosa on October 9. Hide Caption 19 of 33 Photos: Wildfires blaze in California A woman moves horses in Orange as strong Santa Ana winds blow smoke from the Canyon 2 fire toward them on October 9. Hide Caption 20 of 33 Photos: Wildfires blaze in California A firefighter douses flames at a home in Anaheim on October 9. Hide Caption 21 of 33 Photos: Wildfires blaze in California Traffic backs up as people flee Orange on October 9. Hide Caption 22 of 33 Photos: Wildfires blaze in California Santa Rosa residents sift through the remains of a burned home on October 9. Hide Caption 23 of 33 Photos: Wildfires blaze in California The remains of fire-damaged homes and cars smolder at a Santa Rosa trailer park on October 9. Hide Caption 24 of 33 Photos: Wildfires blaze in California A tent structure built for the Safeway Open golf tournament burns in Napa on October 9. Hide Caption 25 of 33 Photos: Wildfires blaze in California Fire consumes a barn in Glen Ellen on October 9. Hide Caption 26 of 33 Photos: Wildfires blaze in California Smoke rises in the hills east of Napa on October 9. Hide Caption 27 of 33 Photos: Wildfires blaze in California A man passes a burning house in Napa on October 9. Hide Caption 28 of 33 Photos: Wildfires blaze in California The remains of fire-damaged homes are seen in Glen Ellen on October 9. Hide Caption 29 of 33 Photos: Wildfires blaze in California A wildfire burns behind the Sonoma Raceway on October 9. Hide Caption 30 of 33 Photos: Wildfires blaze in California A building burns in Napa on October 9. Hide Caption 31 of 33 Photos: Wildfires blaze in California Flames overtake a building in the Napa wine region on October 9. Hide Caption 32 of 33 Photos: Wildfires blaze in California Two women hug as they watch houses burn in Santa Rosa on October 9. Hide Caption 33 of 33

Latest developments

• Wildfires have burned nearly 170,000 acres throughout the state. The largest fires were in Northern California's Sonoma, Napa and Mendocino counties, filling the picturesque landscape of the state's wine country with charred rubble and clouds of smoke.

• Of the 23 people who have died since Sunday night, 13 were killed in the Tubbs wildfire in Sonoma County, officials said. That makes the Tubbs fire, one of 22 blazes burning in the state, the fifth-deadliest fire in recorded California history, according to the Cal Fire website .

• The director of Cal Fire, Ken Pimlott, expects the number of homes and businesses that have been destroyed to rise significantly from 3,500.

• Officials said Wednesday that almost 8,000 firefighters are involved in trying to contain the blazes. The equipment being used includes 550 fire trucks -- at least 170 of which came from out of state -- 73 helicopters and more than 30 planes.

Scores missing

Derek Southard has been worried about his 71-year-old father, Daniel, since he heard Sunday that fires were blazing through Northern California.

Southard, 29, lives with his father in Santa Rosa, California, but he was at a wedding in Monterey on Sunday while his father was at home.

"I had been texting him that day at the wedding. I told him I'm call him that night. And then he never called me back," Southard told CNN in tears. "He texted me at midnight and asked if I was having fun at the wedding. I guess the fire came an hour or two after that."

When Derek Southard got back to Santa Rosa on Monday, the neighborhood was still closed off. He called the sheriff and asked him to go have a look.

"The sheriff said his house was burned to the ground and his car was melted in the driveway, but I've still got my fingers crossed that he made it out somehow," he wrote in a plea on Facebook on Tuesday.

Derek talked to his next-door neighbors, who told him that they barely got out. They said they didn't have time to knock on his dad's door.

Authorities believe communications issues are preventing many of the missing from checking in with relatives.

Among the dead were a couple who relatives said had known each other for nearly 90 years: Charles Rippey, 100, and his wife, Sara, 98.

They died shortly after the Atlas fire -- now one of the largest, at more than 42,000 acres -- began Sunday night, engulfing their home near the Silverado Country Club north of Napa, Napa County spokeswoman Kristi Jourdan said.

"This house was one of the first ones hit (in the subdivision)," their son Mike Rippey told CNN affiliate KPIX on Tuesday.

The couple met each other in grade school in Wisconsin and began a family together after Charles served in World War II, the son told KPIX. They relocated to California after living in the Midwest and on the East Coast, he said.

The son said he believed his father was trying to save his mother when the fire struck."From where they found his body, he was trying to get from his room to her room," he told KPIX. "He never made it. ... There is no way he would have left (without her)."

Elsewhere in the county, part of a veterans home in Yountville, near Napa, was evacuated Tuesday night over fears of approaching flames, but the fire changed directions, so the rest of the residents will stay put for now, Napa Mayor Jill Techel said. Only the most frail -- those in a nursing facility -- left the property in the initial evacuation, Techel said.

"We are set up with buses and everything we need to do if we get the call that a part of town or a part of Napa needs to be evacuated," Techel said.

Ash and rubble

The Tubbs fire reduced cars and homes into burnt piles of ash and rubble in parts of Santa Rosa, a city of about 175,000 roughly 50 miles northwest of San Francisco.

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That fire has burned 27,363 acres and destroyed at least 576 structures between Santa Rosa and the Calistoga area, Cal Fire said Wednesday. It is 10% contained.

A large part of Santa Rosa was evacuated. In the city's Coffey Park neighborhood, homes are in ruins -- the fire seemed to consume everything that wasn't steel, concrete or brick. At some properties, all that is recognizable are the remains of washers, dryers and water heaters.