SPM 09-25-2021: Warm, Dry September Day

Issue Date: Saturday, September 25th, 2021
Issue Time: 9:05 AM MDT

Summary:

Building high pressure over the west has kept air dry and stable, preventing any precipitation across Colorado on Friday. Instead, skies remained mostly clear and temperatures hovered at or above seasonal normals. The Northern, Central, Front Range, and San Juan mountains saw highs in the upper 60s and low 70s, while the Western Slopes, Urban Corridor, Palmer Ridge, and Northeast Plains were in the Upper 70s. Highs were in the 80s for the Grand Valley, Raton Ridge, and Southeast Plains. As expected, no flooding was reported on Friday. For rainfall estimates, check out the State Precipitation Map at the bottom of today’s post.

Air quality across the state has also improved since the summer, when smoke and ozone pollution combined to produce terrible haze over much of the state. Currently, a low-pressure system off the coast of Southern California is helping to keep skies clear of smoke for Colorado – pulling the smoke west and offshore rather than east over the continental US. The Boulder NWS shared the following total smoke forecast, showing the large plume of heavy smoke over California and Nevada.

A weak low pressure system off the coast of SoCal is keeping the smoke out of Colorado from now into this weekend. #cowx pic.twitter.com/bPP2aJRQ4R

— NWS Boulder (@NWSBoulder) September 24, 2021

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 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.