Front Range
AvalancheAndrew McWilliams · Jan 25, 2023 · Front Range
Weather
Broken to overcast skies all day with light snow beginning in the late afternoon. There was no significant accumulation. Cold temperatures did not increase much during the day and began to drop quickly in the late afternoon. Winds were moderate out of the north and northwest.
Snowpack
The snowpack in this area is the shallowest I've seen in the Northern Mountains region. This area is heavily wind-affected near and above treeline with a shallow snowpack below treeline. Below 11,000 feet there is not enough snow for avalanches and snow heights ranged from 40cm or less below 11,000 feet. In sheltered areas near treeline, there was a consistent 50-70cm of snow with a supportable midpack slab that was discontinuous across the terrain. In wind-affected areas near treeline, snow-covered slopes had 70-100cm of snow and the deepest drift I could find was about 200cm. Above treeline was mostly scoured with snow remaining in deep, dense isolated drifts. with the snowpack generally consisting of large bulbous drifts adjacent to bare ground. North and east-facing slopes near treeline have the most snow and are the most likely place to make an avalanche. Extended Column Tests and Compression Tests in snowpits had moderate to hard results that were non-propagating. However, there was a large avalanche that likely ran in the past few weeks on an east-facing slope near treeline. It may have been a natural trigger, but could have been triggered remotely by a skier. A leeward feature failed and ran on the ground and old snow. Besides this avalanche, no other signs of instability were noted.
Avalanche
A large avalanche on an east-facing slope near treeline. There were old ski tracks near the avalanche so it may have been remotely triggered but could have been natural. Based on the look of the debris it likely ran in the past few weeks and multiple paths on the slope ran at the same time.