SPM 09-28-2021: Continued Showers for Southwest Colorado, Ptarmigan Fire Ignited in Summit County

Issue Date: Tuesday, September 28th, 2021
Issue Time: 10:30 AM MDT


The cutoff low traversing Arizona and New Mexico continued to bring late season monsoonal moisture to Southwest Colorado yesterday. There were already showers along the Colorado-New Mexico border in the in the early morning hours. The general eastward progression of the low and daytime heating then allowed for scattered, but more widespread, storm development over the Southwest Slope, San Juan Mountains, Southeast Mountains, even inching up toward the Central Mountains and southern portion of the Front Range Mountains. Showers and thunderstorms lasted well into the evening hours and overnight, however rainfall rates and total accumulation remained low enough to prevent flooding.

The following hyetograph from Red Mountain, a gauge managed by CDOT, shows the day’s steady rainfall beginning in the afternoon and continuing until just before midnight, with total of 0.26 inches of rain.
Other notable totals from CoCoRaHS observers and gauges in Southwest Colorado include:

  • 0.52 north of Durango
  • 0.52 from a USGS gauge at Mancos River near Towaoc, just north of New Mexico border
  • 0.14-0.50 in the Mancos, Dolores, Cortez region of Montezuma County
  • 0.18-0.46 across Saguache county
  • 0.35 in Pagosa Springs
  • Even Trace-0.11 in southwest Colorado Springs and 0.05-0.10 in the San Luis Valley.

For the rest of the state, the day remained dry and unseasonably warm. Highs were in the 80s and 90s across the Grand Valley, Northwest Slope, Urban Corridor, Palmer Ridge, Raton Ridge, and Eastern Plains. The Ptarmigan Fire was ignited yesterday afternoon in Summit County. The White River National Forest twitter account shared the following image of the fire above Silverthorne yesterday. Since the time of the tweet, the fire has expanded to burn around 40 acres.

No flooding was reported on Monday. 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 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.