DENVER (KDVR) — The timing of a surge in monsoon moisture could have a very big impact on your weekend plans.

The National Weather Service has issued a flash flood watch for most of Colorado’s central and northern mountains, as well as the I-25 corridor, from 6 p.m. Friday through at least 9 p.m. Saturday.

Parts of Larimer County, Clear Creek County and Grand County were placed under flash flood warnings Friday afternoon as the first storms rolled through. CDOT said more flash flooding and mudslides are imminent in Glenwood Canyon through the weekend.

“We have been getting isolated, intense thunderstorms,” Kelsha Anderson, a ranger with the White River National Forest, said.

Flash floods caused severe damage along Black Hollow Road in Larimer County on July 20, 2021. (KDVR)

Reconsider mountain travel

Many of the larger slides are affecting areas where wildfires burned last year. However, according to Anderson, many more smaller debris flows are happening on U.S. Forest Service land that has not been burned.

“Even in areas that haven’t recently been burned, it’s a natural process, so if you get enough, rain can overcome the saturation in the soil. And then you get water and debris coming down the channel,” Anderson said.

The possibility of slides in natural areas and burn scars has land managers and outdoor experts concerned heading into a busy weekend for those looking to recreate in the mountains.

“If I was going in a challenging area that had been burned, I would definitely change or cancel.”

Dave Arnett, Douglas County Search and Rescue

“If it looks like it’s going to be raining where you’re thinking of going, maybe question if that’s the best place to be going,” Anderson said.

Even if it is not raining directly where you are, experts say there are still risks to your safety.

“You may not be getting rained on, but if it’s raining up the watershed somewhere at the top of the mountain, you may be impacted or your route to get to that location may be impacted,” Anderson said.

Mudslides ‘beyond any person’s control’

Once you are in the path of a mudslide or flash flood, experts say it may be impossible to get to safety.

“There’s no time really. When you see clouds forming, there is time. When the temperature drops, there is time. But once … a mudslide occurs, you cannot outrun those,” Dave Arnett, with Douglas County Search and Rescue, told FOX31.

Mudslide along Interstate 70 in Glenwood Canyon on July 30, 2021. (Credit: Colorado Department of Transportation)

His team of rescuers and other search-and-rescue teams across Colorado are prepared in case of emergencies. However, Arnett said being rescued from dangerous weather should not be anyone’s primary safety plan.

“They’re incredibly fast, they’re incredibly powerful. People talk about swimming through them, but swimming through mudslides is not a real option. It’s beyond any person’s control, and the time to address it is before it happens,” he said.

Places to avoid during monsoon surges

Arnett recommends outdoor enthusiasts this weekend avoid tight, narrow places; gullies; canyons; and burn scars.

“If I was going in a challenging area that had been burned, I would definitely change or cancel,” he said.

For those planning to continue with their weekend plans in the high country, experts recommend packing extra food, water and gear; to keep checking the weather; and not traveling into the backcountry alone.

Finally, experts recommend budgeting plenty of extra time in case debris flows cause road closures. Interstate 70 through Glenwood Canyon will remain closed through the weekend because of mudslide cleanup and the threat of more slides.