A wildfire that sparked on Colorado’s Western Slope this weekend grew by thousands of acres, destroying two homes. Weather conditions favorable to fire spread are expected to continue.

Colorado Gov. Jared Polis issued an emergency declaration for the Elk Fire on Sunday, a day after lightning sparked the wildfire about 11 miles east of Meeker. By Monday, the wildfire had exploded to more than 4,000 acres and destroyed two homes and an outbuilding, according to wildfire officials. It remained 0% contained.

As the Elk Fire continued to threaten structures and prompt evacuations, the Rio Blanco County Sheriff’s Office wrote in a Facebook post Monday that it anticipates “increased fire activity” due to weather conditions favorable to fire spread. 

Rio Blanco is one of several counties on the Western Slope under a red flag warning advising of dry fuels, low relative humidity and gusty winds this week. The National Weather Service has also issued red flag warnings through Tuesday evening for Routt, Eagle, Pitkin, Garfield and Gunnison counties. 

“Any fire that develops will catch and spread quickly,” the red flag warnings state. “Outdoor burning is not recommended.”

Other parts of the mountains, including Summit and Grand counties, are under a hazardous weather outlook warning of “critical fire weather conditions.” Fire bans remain in effect throughout the region. 

The Elk Fire is one of several wildfires in the state contributing to hazy, smoke-filled skies in the mountains, according to the Colorado Smoke Blog. The Colorado Department of Public Health and Environment has issued an air quality advisory warning of potential health impacts from wildfire smoke through Tuesday morning.

Also burning near Meeker, the Grease Fire was estimated at 1,000 acres and the Lee Fire was estimated at 700 acres as of Monday, according to the Bureau of Land Management. Both fires were discovered over the weekend. There were no estimates for containment on those fires as of Monday afternoon.

The Jack Springs Fire in western Moffat County has grown to about 105 acres and is 80% contained, according to James Michels, the deputy Northwest District manager for the Bureau of Land Management. The fire is burning on both private and BLM White River Field Office.

On Monday morning, wildfire officials said the Coulter Creek Fire that broke out two days earlier north of Carbondale had grown to more than 100 acres, with crews expecting to completely contain the blaze by the end of the day. The wildfire prompted evacuations and destroyed one outbuilding, but other firefighters successfully protected other structures, according to the Carbondale and Rural Fire Protection District.

The Leroux Creek Fire reported Sunday in Delta County also prompted evacuations as it grew to an estimated 700 acres by Monday, according to InciWeb.Wildfire.gov. The wildfire remained uncontained as of Monday.

At the Turner Gulch Fire, which has burned more than 21,600 acres in Mesa County since it sparked in mid-July, firefighters saw increased fire activity over the weekend, with 300 acres of new growth Sunday, according to InciWeb. With 426 personnel on scene as of Monday, the perimeter of the wildfire is estimated to be 49% contained.