SPM 09-09-2017: Scattered, High Elevation Storms with Impressive Rainfall Rates

Issue Date: Saturday, September 9, 2017
Issue Time: 10:15AM MDT


The strong ridging pattern continued its hold over the state again yesterday. Even with the upper-level trough attempting to pull moisture northward, the low-level moisture was confined to the SW states. The light upper-level winds and inversion created another day with hazy conditions from the fires to the north. Moderate mid-level moisture was able to make its way into western Colorado yesterday. With enough moisture over the eastern portion of the state as well, showers and cloud cover were more numerous over the mountains.

Isolated storms began to initiate over the higher terrains in the early afternoon and slowly drifted E/SE. With Precipitable Water near 0.65 inches in the adjacent plains in eastern Colorado, showers produced impressive brief, heavy rain and gusty winds. In El Paso County, CoCoRaHS and USGS stations recorded around 0.3 inches of rain. Rainfall estimates by radar in this area were 1 inch. Just north over Elbert County, a small and strong thunderstorm produced over 1 inch of rain in 1 hour according to radar estimates and a CoCoRaHS station nearby. Over the San Juan Mountains, storm totals were estimated as high as 0.5 inches with a SNOTEL station recording 0.4 inches.

There was no flooding reported Friday. For rainfall estimates in your area, take a peek at 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 accumulation ending time is 6AM of the date shown in the bottom right corner. Also shown optionally are fire burn areas since 2012. 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.