SPM 06-25-2018: End of Weekend Cool Down comes with Hail and Widespread Rain

Issue Date: Monday, June 25, 2018
Issue Time: 09:05AM MDT

Summary:

An early morning frontal passage helped keep high temperatures much more comfortable on Sunday. Behind the front, upslope flow helped kick off a round of early afternoon showers and thunderstorms across the Urban Corridor and Northern Mountains/Front Range. Quick, heavy rainfall accompanied the storms and a funnel was reported near Steamboat Springs. With cooler temperatures and extra lift from the trough over WY, there were numerous reports of snow-like, accumulating hail across the Front Range. The hail was small over the Urban Corridor, but it caused some flooding issues as it clogged gutters and pooled water on the roadways. Gages in the area jumped 2-3 feet but were well below the flooding stage. Total rainfall was estimated to be up to 1 inch with the highest UDFCD ALERT gage in Denver recording 0.63 inches (Rocky Mountain Arsenal).

As the front moved south, more showers and thunderstorms were triggered along the higher terrains. As the storms moved east into better moisture, shear and CAPE, they began producing larger hail and gusty winds. In eastern El Paso County, hail up to 2 inches in diameter was reported. Max 1-hour rain rates around 1 inch were estimated by radar. Further east over the plains, rain rates were estimated a bit over 1.5 inches/hour with 24-hour totals just under 2 inches. A CoCoRaHS station in Yuma County recorded 1.75 inches on Sunday. A wind gust of 66 mph was also reported at the Burlington Airport and a gust of 70 mph was recorded at the Lamar Airport. The eastward moving convection made its way out of the state by 11:30 PM, but a few showers lingered over the eastern plains through this morning.

To see how much precipitation fell in your neighborhood on Sunday, scroll down to 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 24-hour, 48-hour and 72-hour total precipitation contain bias corrections that are not disaggregated into the hourly estimates, so there will likely be some differences. The accumulation ending time is 6AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas (post 2012), which are updated throughout the season to include new burn areas. The home button in the top left corner resets the map to the original zoom.