SPM 09-28-2020: Major Cool-off with Rain/Snow Mix

Issue Date: Monday, September 28th, 2020
Issue Time: 9:40AM MDT

Summary:

A second, stronger cold front dropped through Colorado pretty early yesterday, which caused the high temperatures to be recorded in the morning hours for most locations north. Light showers over the Northeast Plains during the morning were observed, and precipitation increased in coverage after the front dropped through and brought a little moisture/upper air support. For the most part, accumulations were over the lower elevations in eastern Colorado. Even some light snow was observed over the Front Range. The band-like precipitation dropped between 0.05 and 0.20 inches, but isolated totals up to 0.25 inches were possible as MetStorm indicates. This is especially true where the front stalled out along the Palmer Ridge area/east. The highest observation was from a CoCoRaHS station in western Washington County, which recorded 0.13 inches. Flooding was not reported.

High surface winds continued yesterday, although the fire danger dropped off a little from Friday/Saturday due to cooler temperatures. In Gunnison, CO wind gusts up to 53 mph were reported and further south over La Plata County, gusts up to 48 mph were reported. Fire growth was minimal, but containment on the Cameron Peak fire decreased slightly.

It also got very cold overnight, and a Freeze Warning was issued for the Yampa river valley. Temperatures fell to 19F over Craig and 14F near Walden. Other mountain valley locations also reached freezing temperatures, which is typical. Below is a nice picture from the top of Pike’s Peak this morning where rime ice formed. This is when very cold water droplets freeze onto surfaces.

Large ongoing Colorado wildfires update (as of 9:30AM from InciWeb):
Cameron Peak in the Medicine Bow Mountains: 124,026 acres; 21% contained
Middle Fork Fire in Routt County: 7,897 acres; 0% containment
Williams Fork in the Arapaho National Forest: 12,850 acres; 14% contained

To see precipitation estimates over your neighborhood the last 24-hours, scroll down to 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 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.