SPM 06-27-2021: Mud Flow on Grizzly Creek Burn Scar

Issue Date: Sunday, June 27, 2021
Issue Time: 9:40 AM MDT

Summary:

While Saturday was less exciting than Friday, there was still moderate precipitation that fell, largely in the high elevations. Early morning showers were already taking place in the Southeast Mountains and spilled over to the Southeast Plains. As the morning progressed, storms also began to form further in the Northern, Central, and Front Range Mountains as well, before spilling over into the Urban Corridor and then Eastern Plains. The Western Slope and Grand Valley were mostly dry, but some isolated showers did produce quick 0.01-0.15 accumulation in some locations.

The high elevation rainfall was both helpful and harmful yesterday. Scattered showers over the Muddy Slide Fire and Sylvan Fire helped keep fire behavior low yesterday and aid in firefighting efforts. However, a flash flood warning was issued for the Grizzly Creek Burn area yesterday after Doppler radar indicated heavy rainfall. A few days of moderate rain over the burn scar in addition to this heavy rain was enough to cause a mud and debris flow in Glenwood Canyon. I-70 was closed for a period of time yesterday, though has since reopened. MetStorm Live grids in the State Precipitation Map show rainfall over the burn scar as just around 0.50-1.00 inches over the last 72-hours, but still enough to saturate soils and cause runoff. CPR’s Ryan Warner and Stina Sieg tweeted information, including a photo of the slide from CDOT, about the I-70 closure yesterday.

Photo and alternate route courtesy @ColoradoDOT, which calls this “an extended closure.” https://t.co/KJ2HEEjs9p pic.twitter.com/Mja5eQxBwq

— Ryan Warner (@cprwarner) June 27, 2021

For rainfall estimates in your area, check out the State Precipitation Map below.

Click Here For Map Overview

The map below shows radar-estimated, rainfall gage-adjusted Quantitative Precipitation Estimates (QPE) across Colorado. The map is updated daily during the operational season (May 1 – Sep 30) by 11AM. The following six layers are currently available: 24-hour, 48-hour and 72-hour total precipitation, as well as maximum 1-hour, 2-hour and 6-hour precipitation over the past 24 hour period (to estimate where flash flooding may have occurred). The 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.