SPM 08-21-2017: Start of the Next Monsoon Surge

Issue Date: Monday, August 21, 2017
Issue Time: 10:15AM MDT


An increase in moisture over the southern portion of the state yesterday help initiate more scattered showers and cloud cover over the higher terrain. A plume of monsoon moisture and convection from AZ and NM began advecting into the area. The areas that received the most increase in Precipitable Water (PW) were the Southeast Mountains, Raton and Palmer Ridge and San Juan Mountains. PW still remained quite a bit under what is considered high monsoon moisture, but none the less, the moisture return for the next round of monsoon storms has begun.

Only a couple significant thunderstorm affected the state yesterday, and they were located over the climatologically favored regions of Teller and La Plata County. A CoCoRaHS and USGS precipitation gage both recorded around 0.77 inches of rain for the event over the Palmer Ridge area. This was enough to prompt an Areal Flood Advisory, though no flooding had been reported this morning. Radar estimates for the storm total were as high as 2.0 inches. Over La Plata County, another CoCoRaHS station recorded 0.78 inches for the last 24-hour period. Elsewhere, general showers were producing between 0.1-0.2 inches of rainfall.

Cloudiness associated with the disturbance from the south moved over the SE corner of the state last night. These thicker clouds may not completely burn off by late this morning and may cause an obscured viewing of the eclipse today. There is currently a break in cloud cover over northern NM. The hope is that this will advect into southern Colorado this morning and allow a break in the clouds during the peak of the eclipse. However, if the timing isn’t perfect, ongoing convection over NM will cause partly cloudy skies over the southern portion of the state during the event.

To see how much precipitation fell in your neighborhood yesterday, 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 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.