Colorado Front Range Holiday Blizzard

Dec 21-22, 2006

This entry was posted Dec 26, 2006.

Overview

    A major snowstorm impacted the entire Front Range of Colorado on Dec 21-22, 2006. A strong upper level low closed off near the 4-Corners and slowly traveled northeastward over southeast Colorado and western Kansas. Low pressure also developed at the surface, causing strong northerly winds to blow down the Front Range while the upper level system circulated moist air over this and up against the mountains. Wind gusts reached 69 mph (?) at Colorado Springs, 55 mph at Denver International Airport, and ~50 mph in Cheyenne and Greeley as well. Heavy snow began around sunrise (or a few hours before?) on Wednesday (Dec 21) and continued through the day as heavy snow bands developed and moved in from the east. Temperatures were plenty cold for all snow in the region, but far eastern CO and western KS did have some rain.

Impacts

    The storm had extreme impacts on holiday air travel - Denver International Airport was closed for 45 hrs beginning around noon on Wednesday, Dec 21. About 3000 flights were cancelled or diverted in this time period, stranding approximately 4700 people at the airport during the storm. A total of six commercial airports in the region were closed during the storm. Snow drifts of 9-12 feet were reported near or on some runways! DIA opened around noon on Friday (Dec 23) with one or two runways cleared. By Monday the airport had returned to full operations and most of the stranded passengers had been flown out, although thousands of bags were still in a state of confusion. 

    Surface vehicular traffic was also drastically affected. Since the storm was a bit more severe than originally forecast, many people were caught at work on Wednesday, and the rush hour was epic for some. Many cars were abandoned on the major freeways in the Denver Metro area, including US-36 between Denver and Boulder. Eventually, most or all of the freeways were shut down. I-25 was closed through the entire length of Colorado from NM to WY. I-76 was also closed. The National Guard was called out to rescue stranded motorists. The major roadways were gradually reopened Thursday and Friday. 

     To put this storm into perspective for Fort Collins, I browsed around on the 'net looking for some snow climatology resources. I have summarized my results in a separate entry.

Statistics and Snowfall Totals

    Total snowfall accumulations were impressive, with 20-28" throughout much of the urban corridor, 12-20" out in the Eastern Plains of Colorado, and 30-48" in the Foothills. One area about 15-20 miles north of Fort Collins only received a few inches however, doubtless due to strong local downsloping off the Cheyenne Ridge. In the few sections, I've archived some storm stats from the Denver National Weather Service web page.

This is a map of the daily snowfall reported for Dec 21, 2006 by volunteer observers in the CoCoRAHS network. The map area covers Larimer County.

Here is a zoomed map of Fort Collins for that same day (nearly all the snow had fallen by then, the day before snowfall ranged from a T to 0.5" so this map captures nearly the entire storm).