DENVER — The National Weather Service issued Flash Flood Warnings for both the East Troublesome and Cameron Peak burn scars on Monday afternoon.
As much as an inch of drenching rain soaked the flood-prone burn scars in a short time period on Monday, likely producing some flooding.
The NWS said law enforcement in Boulder County reported flash flooding and debris flow of roads in the northwest portion of the East Troublesome burn area. That warning will be in effect until 8:15 p.m. Monday.
Wildfire burn scars are far more likely to see flash flooding, because the lack of vegetation makes it more likely to run off.
In addition to the burn scar flooding, flood advisories were posted for parts of Jefferson, Clear Creek and Grand Counties as well on Monday. Accumulating hail fell on Interstate 70 between Georgetown and Dumont around 2:30 p.m.
Monday's storms are likely to be slow movers, a common recipe for flash flooding (especially, again, over burn scar areas). Typically, summertime storms move in and out fairly quickly, but Monday's were of a slower-moving variety, increasing the overall flood threat.
Also on Monday, Interstate 70 closed in Glenwood Canyon due to a Flash Flood Warning for the area. It reopened just after 6 p.m.
The National Weather Service issued a Flash Flood Watch for much of Colorado's mountainous terrain through Monday evening. A watch means flooding is possible; a warning means flooding is happening or imminent.
Storms reached the Denver metro area on Monday afternoon, with isolated storms lingering into Tuesday.