SPM 05-23-2018: Scattered Thunderstorms Rumbled, Heaviest Rain Fell in Fort Collins

Issue Date: Wednesday, May 23rd, 2018
Issue Time: 9:30 AM MDT

Summary:

Ample moisture was in place across Colorado yesterday, and daytime heating was able to use it advantageously to trigger scattered showers/thunderstorms across the state. The best coverage occurred over the mountains where orographic effects provided a little additional support for thunderstorm development. Activity across the High Country was garden-variety, resulting in gusty winds and periods of light-to-moderate rainfall. A thunderstorm wind gust of 53 mph was reported in Grand Junction (Mesa County).

The strongest storms of the day, though, occurred over the Urban Corridor, Northeast Plains, Southeast Plains, and Palmer Ridge, where the best combination of shear and instability resided. One thunderstorm “complex,” in particular, used a northerly storm motion to impact the Denver metro area, Boulder, and Fort Collins, dumping small hail and periods of heavy rain. In fact, street flooding was reported in Fort Collins due to accumulating small hail clogging drainage allowing for water to pond across a few roadways and intersections.

For a look at precipitation estimates in your area, please see 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.