Front Range
AvalancheJason Konigsberg, Jeremy Mercier · Dec 19, 2019 · Front Range
Weather
Skies were partly cloudy, increasing to mostly cloudy in the afternoon.
Snowpack
Collapsing, cracking, and recent avalanches. That's about all the information we need but we did dig down to look at the snowpack structure and we measured the snow height. While walking down a 30 degree north-facing slope to dig our first pit we collapsed the slope. More of a moderate collapse than a large thundering collapse. In this area the snow height is 75 cm. The surface was small near-surface facets. In fact the top 15 cm was already faceting as well as the harder slab below. The slab was down to 35 cm and progressed in hardness to pencil hard. Beneath the slab was a soft 10 cm layer of 4 mm depth hoar. In extended column tests we got propagation on easy to moderate taps with the block sliding into the pit. Scary. In a second pit on an east-facing slope the snowpack was deeper at 113 cm. It was felt that this is more representative of near-treeline snow depths in the area. In this pit there was the weak depth hoar at the ground but also an easily distinguishable layer of surface hoar 45 cm from the surface. We got a propagating result on the surface hoar and with continued taps on the depth hoar.
Avalanche
Numerous avalanches D2 in size. Most avalanches only took out part of the start zone. There were older blown in crowns that may have been wider but it was hard to tell. A few avalanches were fresh, probably within the last 72 hours. The trigger for these newer avalanches is unkown but I would suspect remote triggering from snowmobiles based on the tracks around the avalanches. Some avalanches covered up old snowmobile tracks. The avalanches coded below probably only scratch the surface of recent activity.