SPM 06-22-2018: Isolated Summer Solstice Thunderstorms

Issue Date: Friday, June 22, 2018
Issue Time: 09:40AM MDT

Summary:

A mid-level shortwave trough moved through the northern portion of Colorado yesterday afternoon during peak heating. This helped enhance and kick off a little more thunderstorm action over the northern Colorado mountains and Cheyenne Ridge. While, moisture was plentiful at the surface for some rainfall, quick storm motion prevented the isolated thunderstorm, up north, from dropping heavy precipitation over the Urban Corridor. Radar estimates were just over 0.5 inches/hour. Stillwater Creek SNOTEL recorded 0.1 inches of precipitation on Thursday. Another couple isolated thunderstorm fired off the Palmer Ridge and Raton Ridge during the evening hours. Low dew points plus quick storm motion again limited the thunderstorm’s total rainfall. A Mesonet in Sedalia picked up 0.31 inches. After the latest sunset of the year, instability rapidly dropped off and the storms came to an end. There was no flooding on Thursday.

Below is the current streamflow map for the state of Colorado. Streamflow continues to be much below normal for the majority of the high country with the bright red dots representing the lowest recorded streamflow at that location. The reservoir storage maps for June will come out around July 7. The May maps showed reservoir storage was close to or above 100% for all basins. The exception was the San Miguel, Dolores, Animas and San Juan Basin, which was at 75% of average. With the very hot and dry conditions this last month, the June report will likely show decreases in storage across all basins.

To see how much precipitation fell in your area on Thursday, 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.

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.