SPM 08-18-2017: Further Drying On Thursday, But A Few Severe Storms Across The Far East

Issue Date: Friday, August 18, 2017
Issue Time: 9:35AM MDT


Quieter weather continued to overtake most of the state on Thursday as a cool front and dry air advection from the west limited instability. A few nuisance showers and weak thunderstorms popped up over the favored parts of the western Palmer Ridge and Front Range, scooting southeastward before dissipating. Up to 0.5 inches of rainfall occurred with the strongest of these storms, though this was by far the exception with most places recording a few tenths at best.

The only major exception to the calmer weather was in far eastern parts of the state where a few thunderstorms briefly turned severe in Baca and Yuma counties. The former storm was warned for large hail and gusty winds, but not much rainfall. The latter storm produced up to 1.5 inches of rainfall in about an hour over a localized area right along the New Mexico border. Fortunately, no flooding or severe weather reports were officially tallied with these storms, although they occurred over very rural areas with few observers and gages.

Finally, with the break in the active weather, we take a look at the extremely active period that occurred over the Arkansas River basin over the past 30-45 days. Below is the Arkansas River hydrograph at Las Animas. Note that after the spike on July 27, the river has stayed well above normal levels for the better part of 3 weeks. The volume of 30-day rainfall that fell in the area that drains into the gage below is near record levels. Fortuitously and quite surprisingly, the rain was spread out in time just enough to limit major flooding concerns. With the monsoon season still in its primetime, we will be carefully watching to see what the next few weeks’ worth of rainfall bring.

For rainfall estimates in your area, check out 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 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.