Front Range
AvalancheRyan Lewthwaite · Dec 2, 2019 · Front Range
Weather
A mild afternoon with 27F and clear skies. There was a light breeze from the southwest in protected areas, while winds at Ridgeline were transporting any new snow to lee aspects. An overnight temperature inversion helped create surface hoar in many below treeline areas.
Snowpack
Coverage is still sparse on many below treeline areas and southerly aspects. The north through east aspects near treeline are the deepest and have been effected by wind transport and sun degradation. After climbing above treeline I spotted 12 avalanches in the Current Creek basin that likely occurred before the weekend. Most of the avalanches were loose dry sluffs, a few were cornice fall, and one was a hard slab that stepped down into deeper layers and eventually to the ground. Several of the loose dry avalanches were on southerly aspects, while most were oriented north through east with the prevailing southwest winds. Surface hoar was evident in wind protected areas but was relatively small in size (1mm). Areas exposed to the wind have firm drifted slabs overlying soft snow that may be up to 20cm thick. On south through east aspects there exists melt-freeze crusts in the mid-snowpack, which are surrounded by unconsolidated facets. These persistent grain layers are contributing to the instability which is evident when cracking or collapsing occurs as you travel across the landscape. In the exposed, above treeline terrain, slabs of wind-drifted snow can be found with varying densities. Some of these slabs are breakable and hollow underneath and others are pencil hard, holding the weight of a person. Top loaded and cross-loaded features above treeline are the most suspect to avalanches. The R2D2 slab avalanche that occurred on 11/30 in the "headwall" was oriented northeast and aligned with the poor snowpack structure. The avalanche stepped down into layers that have shown common failure plains in snowprofiles.
Avalanche
No new avalanches. But 12 avalanches were seen in this basin and are associated with the most recent snow and winds from 11/30.