SPM 09-12-2017: Rainfall Coverage And Intensity Increased

Issue Date: Tuesday, September 12, 2017
Issue Time: 11AM MDT


A weak disturbance and above normal moisture content was enough to increase thunderstorm coverage across Colorado on Monday. As is frequently the case, the vast majority of storms were garden variety, producing a few tenths of an inch of range over most of the High Country and adjacent foothills above about 7,000 feet. However, a few storms stood out from the rest. The storm of the day was likely in western Elbert County, where a quick 1 inch of rain fell in less than 30 minutes. Radar-enhanced estimates suggest up to 2 inches of rain fell in 1 hour. Another area of enhanced rainfall activity was in Chaffee County where up to 1.5 inches of rain fell in about 1 hour or less. West of the Continental Divide, rainfall amounts were lower with up to 0.6 inches falling mainly over the higher elevations of the San Juans. Small hail was reported in Routt County, south of Steamboat Springs from a small cell during the late afternoon hours.

Flooding was not reported on Monday. For rainfall estimates in your area, check out our 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 6AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas since 2012. The home button in the top left corner resets the map to the original zoom.

Note: We have identified a possible underestimation in QPE over the southwest part of the state. We are working to on this issue, and will provide an update as soon as possible.