The Derby fire, a wildfire northeast of Glenwood Springs, grew 1,000 acres by Sunday.

The fire caused by a lightning strike a week ago has reached nearly 5,250 acres, a news release from the Derby Fire Information said Sunday morning. It still remains at 0% containment.

The Derby fire is located in the White River National Forest about 13 miles north of Dotsero, a small town along Interstate 70 in Eagle County near where the Glenwood Canyon begins.

There are 525 total personnel working to slow the fire, 100 more than the previous day.

The area could get some needed rain Sunday, officials said, but that may also increase the chance of lightning that could fuel or start new fires. Especially in drier areas. 

Most of Eagle County was under extreme drought this week and the west side of the county was in the midst of an exceptional drought, according to the U.S. Drought Monitor. 

Monsoon moisture is expected to feed afternoon thunderstorms around the Western Slope beginning Sunday and going into next week, according to the National Weather Service office in Grand Junction.

“The much anticipated cooler and wetter pattern has arrived,” the NWS posted early Sunday morning on X. “Widespread showers and thunderstorms are expected this afternoon, with heavy rain, frequent lightning, small hail, and gusty winds the main threats.”

There’s a 60% chance of precipitation in the area where the fire is and thunderstorms expected after 3 p.m. Sunday.  

The fire was more active on the east side Saturday, the  news release said. Though outflow winds have pushed the fire south.

Three aircraft have dropped water and flame retardant on the southeast side of the fire. Firefighters have strengthened control lines on perimeters of the fire and will continue to do so Sunday if weather permits, the release said.

A helicopter pilot helping mitigate the fire sustained minor injuries after the craft he was flying ended up in a lake just after 4 p.m. Friday.

Officials have extended the closure of Colorado River Road further south and closed access to Coffeepot Road. Eagle County still has an evacuation notice for residents of Sweetwater Road and Red Dirt Creek.

Areas along the Colorado River Road beginning north of I-70 are under pre-evacuation status.

Officials said personnel worked to protect more than 500 structures with sprinkler kits and removing extra fuels for the fire.