Recent burn areas especially susceptible to floods and mudslides
By Summit Voice
SUMMIT COUNTY — What a difference the monsoon makes. After several weeks of parched conditions and extreme fire danger, a big slice of the Colorado high country is suddenly facing a new threat.
Slow-moving thunderstorms could drop up to two inches of rain on ground that’s either saturated with moisture or scarred by recent wildfires, leading to potentially dangerous flash floods, especially in the Four Mile, the Waldo Canyon and High Park burn scars, according to a flash flood watch issued by the National Weather Service.
The Boulder-based forecasters said residents of those areas should stay tuned throughout the day for subsequent updates, emphasizing that a flash flood watch means flooding is possible, but not imminent.
Several mudslides and debris flows were reported Friday in the High Park area. The watch covers the Front Range mountains from the Wyoming border to south of Colorado Springs, as well as the Western Slope from Routt County down through parts of the San Juans.
The moisture is courtesy of a monsoonal plume with moisture available for precipitation ranging from 150 percent to 200 percent of normal. Rainfall rates of 1 inch per hour are possible under the heavier showers, with some training possible, which means storms could track repeatedly over the same areas.
Soils in burned areas are often unable to absorb even small amounts of moisture, so the rain runs off almost instantly, causing creeks and streams to flood much faster than normal.
The weather service recommends against driving in areas where water covers the roadway. Even a few inches of water can be strong enough to sweep away a vehicle.
Hikers should be aware of rising waters and prepared to seek higher ground, away from swelling streams.