20-21

Observed natural avalanche at Fairy Lake when we snowmobiled to the lake today. Avalanche appeared to be naturally occurring. The crown was roughly 150ft wide varying from 2.5-.5ft deep. I took these pictures in passing on my snowmobile. The large part of the crown appeared to be on the new snow interface however some of the slide appeared to be a glide as it ripped down to the rocks on the face. I did not expose myself for long enough to get a very clear read on the slide other than that. The section where the crown broke deep did not travel very far. There is still notable amounts of hang fire. I would say the slide was r2-d2.

GNFAC,
Toured at Bacon Rind today, ski conditions were exceptionally good. Seemed like 4” of new snow, it snowed another inch while we were up there, moderate winds at the ridge top were moving snow. We got 2 whumphs while skinning around, a new record low!
Spencer

A 100’ wide by 12”-24” deep avalanche was triggered by a skier on a North East aspect of Woody Ridge at 9000’. Skier was carried and partially buried after arresting on a tree. Photo: Anon

S2 snow most of the day. Light winds, overcast.

Extensive large whumpfs and cracks at about 7000-7800 feet. Snow was unsupportable in many places, others had a clear slab in the midpack you could feel with a pole probe.

Dug a pit at 7500 ft on east aspect. Haven't had a chance to put into snowpilot yet, but here is the jist. 110cm HS. 20cm precip particles on top (F), middle of the snowpack was 1mm rounding facets and/or faceting rounds (4F) and fairly cohesive. Bottom 30cm was large facets bordering on depth hoar. Clear cups forming and 3-4mm or so (F). CT18. ECTX, which surprised me... I should have done a second test. Was able to propagate on the depth hoar using a snow saw easily, though did not perform full PST.

A 100’ wide by 12”-24” deep avalanche was triggered by a skier on a North East aspect of Woody Ridge at 9000’. Skier was carried and partially buried after arresting on a tree. The area was short pitches with rollovers and pillow/shelf features. Once the skier was in avalanche terrain the wind loaded storm slab released exposing a faceted layer which the new snow had not bound with. The release occurred where the slope went from 20 degrees to 30 degree terrain. A pit dug the previous day (2/4/2020) on the same slope resulted in an ECT 50 + and a CT 38. Afterward that day we proceeded up the ridge to find wind slabs formed at the top of the ridge which would release when cut. Today, the snow felt stable on the ascent through trees and on tree covered ridges. When we turned around in what we considered “mellow”/“putt putt” terrain due to an intensifying storm and the day becoming late we skied through some exposed ridges and drops. First skier saw no avalanche activity through broken up terrain. Second skier triggered the slide on the first turn. After the event a third skier skied the tree covered ridge used for the ascent and was clear. Whompfing was observed in the trees below the pillows after the event likely from an increase in temperature and loading of the slope.

AVALANCHE WARNING for Bridgers