CARSON CITY, Nev. — The alert came via text Saturday: Leave. Now.

So Clay Cunningham and his wife packed what they could and fled their house in Meyers, Calif., near South Lake Tahoe.

But nearly as soon as they reached their daughter’s home, another evacuation order arrived. The Cunningham’s moved again, to nearby Kingsbury, Nev.

Then on Monday, the raging Caldor Fire began to descend from the Sierra Nevada mountains, threatening much of the populated Tahoe region. Thousands of people on the lake’s western and southern shores were forced to evacuate.

The Cunninghams were part of the exodus, driving in multiple cars with their two adult children and small dog. By early Tuesday morning, they had reached the Carson City Community Center in Nevada, where they set up a tent in a grassy patch next to the parking lot.

Experts warn that the Caldor Fire, which has burned about 192,000 acres, could continue its march toward Tahoe in the next few days, destroying thousands of structures and putting lives at risk.

Craig B. Clements, a professor at the Wildfire Interdisciplinary Research Center at San Jose State University, said the Tahoe region has always been vulnerable to fires. But what’s unusual this time, he said, is the size of the burn.

“For a fire to be burning on such a large scale is quite concerning,” he said.

He said the fire, which has only about 16 percent contained, has been tough to control. Firefighters are standing by to extinguish embers as they fall onto roofs and lawns, but because of the scale, “it will be a challenge to protect everything,” Clements said.

Cunningham said he’s grateful for the kindness he has encountered in Carson City, where neighbors have been delivering food and coffee. On Tuesday morning, two women stopped by the evacuation center in a Subaru packed with supplies.

But he’s worried about whether his home will burn and how long he might have to stay away. Cunningham’s family was lucky to get a hotel room in Carson City through the weekend. But his son, who booked the rooms, said hotels were nearly full.

Experts also warn that wind over the next few days could make the situation in Tahoe particularly volatile.

A trough, or a dip in the jet stream, is moving through the region and bringing gusty winds from the southwest and very dry air. A red flag warning for critical fire weather is in effect until 11 p.m. Wednesday, with the strongest gusts expected Tuesday afternoon and evening, particularly at higher elevations, where the Caldor Fire is burning.

Eric Kurth, a fire weather forecaster with the National Weather Service in Sacramento, said that while this is a fairly typical weather pattern for this time of year, it is a “significant issue” with large fires burning in the mountains.

Back-to-back dry years followed by a very hot summer have led to record dry vegetation, even in alpine areas.

In addition, the very low humidity, along with poor humidity recovery at night, is allowing fires to burn actively through the day and night.

“When you combine these together you have a very dangerous situation,” he said.

Although the wind pattern is coming off the ocean and would normally bring moist air, that moisture hasn’t traveled far enough east to reach the Caldor Fire.

“That initial rush of air is unfortunately still quite dry up in the mountain areas,” Kurth said.

The gusty and dry conditions are expected to continue through late Wednesday for the Northern Sierra and the Lake Tahoe area. “Even though today is the strongest, we are not out of the woods on Wednesday either,” he said.

A study published this year found that Western forest fires are moving into higher altitudes as temperatures rise with climate change, reaching elevations that previously would have been too wet to burn.

On Monday, the Caldor Fire became the second fire in California history to cross the Sierra Nevada, traveling up and over the highest ridgetops.

“We haven’t had fires burn from one side of the Sierra to the other,” Cal Fire Director Thom Porter said in a news conference Monday. “We did with the Dixie; now we have with the Caldor — two times in our history, and they are both happening this month.”

At local evacuation centers, some residents are bracing for bad news.

At the Fuji Park Evacuation Center, about six miles from Carson City Community Center, Dan Barosko and his 138-pound Pyrenees dog Lilie evacuated from his home in South Lake Tahoe on Monday afternoon.

Barosko had been watching the fire and started packing about a week ago. But the warning to leave came fast.

He got a text on his cellphone and a call on his landline in English and in Spanish saying there was an evacuation warning. Ten minutes later, it turned into an evacuation order.

It took him an hour and a half to go three miles in the South Lake Tahoe traffic. Ash was falling on his car and embers were flying. As he was driving through town, businesses were closing up.

Since he doesn’t have a smartphone or computer, Barosko is getting all of his information from an old radio with headphones. He is listening to local Reno radio station 91.1 FM, which gives updates every 30 minutes.

Barosko moved to the Tahoe are in the 1970s, he said. He was drawn to the region for its natural beauty. “It’s not going to be the same beautiful lake once [the fire] is over,” he said.

Barosko isn’t sure what he’ll find when he returns home, whether his house will survive. “This isn’t how I wanted to write this story,” he said. “I have a hole in my heart right now.”

Amanda Erickson contributed to this report.