LA PLATA COUNTY, Colo. — Officials told residents of nearly 350 homes in southwest Colorado to be prepared to leave Thursday if dry thunderstorms, high heat and gusty winds spread a wildfire that has blackened more than 50 square miles and is seen as extremely dangerous for firefighters.

“With the storms comes the lighting and those gusty winds. We’re definitely asking the firefighters to keep their eyes open and their heads up and pay attention to any changes in the weather,” fire team spokesman Jamie Knight told The Durango Herald.

About 1,900 homes have been evacuated since the 416 Fire began June 1, though 560 homes were declared safe late Wednesday, allowing some residents to return.

“We were just happy to get back. We were tired of living out of suitcases. You can imagine four people and two large Labs in small hotel rooms,” Joe Hardman told the Herald after going home with his wife, two daughters and two Labrador retrievers.

The fire forced the San Juan National Forest to close but hasn’t destroyed any homes.

More than 1,050 firefighters backed by air tankers and water-dropping helicopters had contained 15 percent of the blaze, said Cameron Eck, spokesman for the Rocky Mountain Incident firefighting team.

An estimated 32,076 acres had burned as of Thursday night.