LOS ANGELES — Crews were turning a corner on a 990-acre wildfire burning near Wrightwood in the Angeles National Forest, reaching 27% containment Tuesday morning.

The blaze, which ignited Saturday, exploded in size over the weekend as firefighters contended with soaring temperatures and a drought-dried landscape primed to burn.

“Fighting this fire has been especially challenging due to dense vegetation, steep terrain, and high and erratic winds,” the Forest Service said in its latest update.

Nearly 700 firefighters have been attacking the fire from the air and ground to lay containment lines and extinguish some flames, with favorable wind conditions and cooler temperatures on Monday enabling them to make some progress.

But Tuesday could present new challenges as temperatures in the area creep back up and gusty winds return. The National Weather Service has issued a wind advisory in the San Bernardino County mountains, where wind gusts of up to 40 mph are possible through 11 a.m.

Heat was also expected to return this week, said Adam Roser, a meteorologist with the weather service in Oxnard.

“Temperatures around the fire will be in the upper 70s today and warming up through tomorrow and Thursday, when we’ll get into the 80s over there,” he said. “Humidity will be going down to around 10%.”

In fact, the warming trend will be felt throughout the Southland, where temperatures in Los Angeles County could soar as high as 105 degrees in the valleys and 100 degrees in mountain areas on Wednesday and Thursday, the weather service said.

Palm Springs and Thermal could hit 109 and 110 degrees, respectively, by Thursday, according to the forecast.

The South Coast Air Quality Management District has also issued a smoke advisory warning of potentially unhealthy conditions in areas near the fire.

“If you smell smoke or see ash due to a wildfire, limit your exposure by remaining indoors with windows and doors closed or seeking alternate shelter, and avoiding vigorous physical activity,” the agency said.

Evacuation orders spurred by the fire remained in place Tuesday, according to the San Bernardino County Sheriff’s Department, including Desert Front Road and Wild Horse Canyon; Highway 2 south to Lone Pine Canyon Road; and Wright Mountain Road to Sheep Creek Drive.

An evacuation center has been established at Serrano High School in Phelan, and animal evacuations are available at the Devore Animal Shelter and San Bernardino County Fairgrounds. Residents are advised to contact San Bernardino Animal Care and Control in advance for animal evacuation assistance.

An evacuation warning was also in place for the rest of the community of Wrightwood.

The cause of the Sheep fire remains under investigation, the Forest Service said.