SPM 08-14-2019: Heavy Rain for the Far Eastern Plains along with a Tornado and a Possible Record Breaking Hailstone

Issue Date: Wednesday, August 14th, 2019
Issue Time: 10:20AM MDT


Tuesday was another busy day on the severe weather front, which was not too surprising given the atmospheric pattern. A strong dry line setup over the eastern plains with westerly flow aloft, and helped produce some very strong thunderstorms in a high shear and CAPE environment. Storm motion was fairly quick to the southeast, but there were still some impressive 1-hour totals (around 2.25 inches)! A tornado watch was issued for the Northeast Plains at 1PM and the storms initiated shortly after along the boundary. The storm produced a couple of tornado touchdowns in Yuma and Kit Carson Counties, but hard to tell in some pictures due to the tornado being rain wrapped. Large hail also accompanied the storms. There was a ~5 inch diameter hailstone reported in Bethune via Twitter. This will still need to be verified, but if it does, this will be a new state record. See: https://climate.colostate.edu/records.html for more information about hail records. There were several other reports of large hail with these storms ranging from 1.75 inches to 2.75 inches

Not surprisingly, there was flooding reported near Burlington where radar estimates around 1.75 inches fell. There were two Flash Flood Warnings for the County between 3 and 6PM. A CoCoRaHS station in town recorded 1.34 inches for the event. In Stratton, CO (north, central Kit Carson County) there was a CoCoRaHS station that reported 1.58 inches, which was the highest report of the day for the eastern plains. Storms then moved south along the tail end of the MCS in Kansas caused some more rainfall over the Southeast Plains. Additional storms fired with these outflow boundaries over the area in the high moisture environment. Radar indicates just over 1 inch fell with more general storm totals around 0.6 inches. Light to moderate rain continued into this morning.

An outflow boundary from the Northeast Plain storms initiated another set of thunderstorms over the northern Front Range and adjacent plains. When it pushed back west, it broke the cap over the foothills. Hail between 1 and 1.25 inches fell between 10 and 11PM over the Weld/Larimer/Boulder County intersect. A rain gage just south of Wellington picked up 0.5 inches along with an ALERT gage in Longmont. Radar indicates up to 1.5 inches of rain fell just southeast of Longmont. There was no flooding reported with these storms as of this morning.

To see estimated precipitation totals over your neighborhood on Tuesday, 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 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.