SPM 08-09-2018: Rare Morning Tornado in Weld County

Issue Date: Thursday, August 9th, 2018
Issue Time: 09:20 AM MDT


Interesting start to Wednesday morning with thunderstorms well under way over the Northeast Plains from the prior night. These storms worked their way south through the morning/afternoon and produced some severe hail (1.25 inches) and gusty winds. Even a rare morning tornado was reported at 6:30am in Weld County. There was quite a bit of convection on the west side of this disturbance. A gust front from the storm pushed up against the Front Range and brought fog to the Urban Corridor by mid-morning. This pretty much killed all the chances for convection in the afternoon hours. With dew points in the 60Fs, this system was able to drop some heavy rainfall as it quickly progressed south. Max 1-hour rain rates just under 1 inch were estimated from radar. A CoCoRaHS station near Woodrow reported 0.97 inch of rain from the thunderstorm complex.

During the afternoon, more isolated thunderstorms popped up over the southern Southeast Mountains. Two flash flood warnings were issued for the Spring Creek burn scar, but thankfully no flooding was reported. Radar estimated this area received up to 1.5 inches of rainfall, but this total did not fall over the burn scar itself. Convection ended around 6PM with some light showers over the higher terrains through early morning.

To see how much precipitation fell over your area, 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 7AM 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.