SPM 06-18-2019: Active Day Across Colorado with Heavy Rain, Flash Flooding, Hail, Wind, and a Tornado over the Eastern Plains

Issue Date: Tuesday, June 18^th, 2018
Issue Time: 10:35 AM MDT

Summary:

Few areas of the state remained dry yesterday as a shortwave passed over the state, helping spark numerous showers and thunderstorms. A surface low on the central eastern plains helped pull in some high moisture values for heavy rainfall under slow steering winds. A break in the clouds by mid-morning allowed for surface heating and convective instability to build, which helped produced several severe thunderstorms over the Grand Valley, Southeast Plains, Northeast Plains and Urban Corridor. A severe storm near Chivington in Kiowa County produced flash flooding (causing parts of Colorado 96 to wash out), a weak tornado and 1.75 inch hail. Radar estimates up to 4 inches of rain fell in Kit Carson County over a 2-hour period, which is a 1 in 200 year event.

Multiple hail reports were recorded in Pueblo County, with the largest hail recorded at 2.5 inches. Weak upper level winds allowed the storms to linger within the area, resulting in a rain report of 2.25 inches and winds up to 69 mph at Pueblo Memorial Airport. Glade Park in Mesa County recorded 0.75 inches of rain. Storms yesterday also produced a lot of wind. A gust of 70 mph caused downed power-lines in Baca and a gust of 62 mph was recorded over Boulder County associated with a storm in the area. For the storm in Boulder, the UDFCD ALERT network recorded an inch of rain in 30 minutes. As of this morning, there were no flood reports with this storm.

As far as riverine flooding, gages remain high over the Arkansas River downstream of Pueblo Dam. The Nepesta gage temporarily dropped below Action stage, but has returned this morning. There was also an increase in flow at the La Junta gauge. Over the southwest, there were reports by emergency management of minor flooding issues along the headwaters of the Rio Grande and in central Saguache County. This will continued to be monitored in the daily FTB.

For a look at yesterday’s widespread precipitation, 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 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 7AM of the date shown in the bottom right corner. Also shown optionally are vulnerable fire burn areas (post 2012), which are updated throughout the season to include new, vulnerable burn areas. The home button in the top left corner resets the map to the original zoom.