SPM 08-20-2017: Decreased Moisture Limits Showers to Eastern Plains

Issue Date: Sunday, August 20, 2017
Issue Time: 10:05AM MDT


It has just been nothing but beautiful weather the last couple of days across the state. Yesterday was no exception. Limited moisture under the ridge reduced rainfall coverage over the mountains and adjacent plains. Storms produced gusty winds rather than heavy rainfall. In low moisture environments, when rain falls through a warm, dry layer, most of the rain will evaporate. As this happens, the air’s temperature will also be reduced in a process called evaporative cooling. The cooler air is less dense and quickly sinks, which helps produce the gusty winds.

A couple stronger storms were able to form over the eastern plains along the CO/KS border and Baca County where moisture was a little higher. A CoCoRaHS station in Baca recorded 0.8 inches for a warned severe thunderstorm. Radar rainfall estimates were just over 1 inch. Another later evening storm formed over the Palmer Ridge. A CoCoRaHS station in Hugo reported 0.25 inches, while radar estimates were just over 0.5 inches. Most of the general showers that formed yesterday produced between 0.1-0.2 inches.

To see how much rainfall fell in your area, scroll down 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 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.