SPM 09-21-2020: Windy Over the Northern Mountains with Scattered Evening Storms

Issue Date: Monday, September 21st, 2020
Issue Time: 10AM MDT

Summary:

It was another beautiful September day across the state, minus the haze, with afternoon cloud cover over the mountains. There was a nice cloud deck over the southern Front Range/Urban Corridor in the morning associated with a weak boundary. This kept temperatures a bit cooler than they normally would have been. With the speed max overhead, there were windy conditions over the Front Range and Northern Mountains during the afternoon. Gusts reached between 30 and just under 40 mph, which helped expand the ongoing fires in the area.  As far as rain, scattered light showers developed over the Front Range during the early evening hours and spilled into the adjacent plains. Most storms began to evaporate as they moved into the lower elevations, but some light showers were observed in Weld County on the southern side of the Cheyenne Ridge. Not many observations in the area, and QPE was under 0.25 inches (between 0.10 and just under 0.20 inches). Light showers also formed this morning along a convergence boundary produced by the lee trough. As anticipated, flooding was not forecast.

Large ongoing Colorado wildfires update (as of 9:55AM from InciWeb):
Cameron Peak in the Medicine Bow Mountains: 104,157 acres; 15% contained
Middle Fork Fire in Routt County: 6,187 acres; 0% containment
Williams Fork in the Arapaho National Forest: 12,320 acres; 16% contained

To see precipitation estimates over your area the last 24-hours, scroll down to the State Precipitation Map below. Due to only light rainfall the last couple of days, the map continues to look blank.

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 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.