This natural avalanche crossed the groomed cross country ski trail likely between the evening of 2/13 and the morning of 2/14. This dry wind slab avalanche was a size 3 with destructive potential also a 2+ (R3D2+). In plain terms it was medium relative to the whole avalanche path; and could easily bury and kill a human. The deepest part of the debris was nearly 7 feet while the width was over 500 feet and the avalanche ran almost 1800 vertical feet. The crown was 2.5 feet at its thickest and originated on a north/northeast aspect around 4000 feet in elevation. This is a fine example of the potential for avalanches to occur in places where unaware recreationist may be effected, who may not posses the proper safety equipment. Avalanches can runout onto low angled slopes with enough volume and the right alpha angle.
Observation: Hatcher Pass
Location: Archangel Valley recon
Cross country skied up Archangel Valley towards Reed Lakes Trailhead. Planned to documented recent avalanches in the area and assess surface snow conditions. Saw several recent wind slab avalanches including one that crossed the groomed ski trail as reported by Tim Escher on 2/14.
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
I saw several avalanches today that we did not see during yesterdays field day. The southeast side of Marmot had 3-4 avalanches D2 or larger that came down prominent drainage features. Although these paths face east and southeast the cross-loading nature of the winds and terrain built slabs on north and northeast aspects which failed below the newly formed slabs, some exposing the ground.
I saw a large natural D2 on on Arkose Ridge on a northwest aspect at around 4500 feet.
On Peak 5100 a large natural D2 avalanche on a southwest aspect at 4000 feet.
On Peak 4068 a natural D1.5 on a northeast aspect at 4000 feet.
Partly cloudy skies with 33F degrees at 2200 feet with light winds near the Archangel Lot. The winds were moderate with temps around 31F degrees near Independence Lot at 3000 feet. Blowing snow was observed at ground level and along higher ridgelines.
Soft dry snow in wind protected areas while open areas and wind exposed slopes the surface was firm. Below 2000 feet the snow surface was moist and glistening.
Wind loaded slopes that have not avalanched may still hold the potential to be triggered by human interaction on aspects that face southwest through northeast. It looks like natural avalanche activity is decreasing over time.
Natural Wind Slab Avalanche on Arkose Ridge Northwest Aspect at 4500 feet 2/15
Natural Wind Slab Avalanche in Fern Path off Marmot Southeast Aspect at 3800 feet 2/14
Natural Wind Slab Avalanche in Fern Path off Marmot Southeast Aspect at 3800 feet 2/14