SPM 09-26-2017: Precipitation Coverage Decreased, But Clouds Persisted For Some

Issue Date: Tuesday, September 26, 2017
Issue Time: 11AM MDT


The past weekend’s storm system slowly departed from Colorado on Monday, and precipitation coverage and intensity took a big downward step. Nonetheless, scattered showers and weak thunderstorms rumbled in two separate areas of the state: one area in the Front Range and Palmer Ridge and a separate area in the Southeast Plains. With limited instability, rainfall rates were subdued, especially compared to Saturday and Sunday. Highest 24-hour totals of 0.5 – 0.75 inches were reported in El Paso and Baca counties, falling over a 2-3 hour period. In other regions, most totals were limited to 0.25 inches or less.

For areas west of the Continental Divide, plenty of sunshine resulted in a boost in temperatures to just below seasonal normal. However, for areas to the east, a pesky low cloud deck insulated the cold air near the surface. High temperatures continued to run up to 20F below normal on Monday.

With the storm system moving away, we can now assess the total precipitation over its roughly 72 hour duration (see map below). Widespread amounts exceeding 1 inch were reported across the eastern third of the state. Of particular note were areas in southeast Colorado that received over 2 inches (with local maximums up to 4 inches). A separate maximum was observed in the Front Range where up to 2 inches of rainfall occurred in Larimer and Weld counties. Finally, another area of enhanced amounts was over the Central Mountains and Grand Valley where between 1 and 1.5 inches of precipitation (both rain and snow) fell.

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.