Avalanche

Croy

Scott SavageSoldier & Wood River Valley Mtns
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Observation photo 1

Quick report

Collapsing
specific

We avoided middle elevation starting zones (slopes steeper than 30 degrees, above 6500') on the northern half of the compass. We saw enough recent wind loading and minor snowpack collapsing—and knew there was a good chance the ugly surface hoar or faceted snow was buried 2-3 feet deep where we planned to ski—to not want to push things. We felt comfortable traveling in avalanche terrain below 6500', where there is about a foot of settled storm snow above rain runnels and thick crusts. Below the rain line, we felt the chances of either triggering or remotely triggering a large slide were very low.  

Avalanche was a small D1 wind slab on Della (see photo and caption). We had 5 or 6 collapses, with some occurring with after multiple people were on the skin track. They traveled about 10-20 feet, and all seemed to occur on the 1/31 weak layer/basal facets. All occurred either in the flats on the valley bottom, or on wind-loaded ridges. There was more collapsing today than on Feb 8th in the same general area.

Weather

Air Temp
Teens, low 20s
Cloud Cover
few
Wind Loading
previous
Rain Elevation
N/A during last storm - snow to valley floors
Recent Snowfall
20
Snow Avail For Transport
moderate amounts

Light W winds, clear in the morning with increasing clouds PM.

Snowpack

This was a quick trip - no formal stability tests performed.

The 2/13-14 storm had some E wind in this part of Croy Canyon, wind-loading places that were not wind loaded on February 8th. During the 2/13-14 storm, there was more wind-loading on the actual ridges than on the slopes on either side. We didn't see any fresh wind slabs below 7300'. 

Hand pits and non-standard hand tests showed a potential failure layer at the 2/13 interface: it was failing a few cm below the top of the 2/13 interface, on a layer of small FC below a denser wind crust. There were small FC above the wind crust, but it was touchier below the crust. 

Direct solars were getting moist/damp by 1300hrs. 

 

 

Avalanche

Della Mtn: Small natural wind slab avalanche (D1) released sometime between 3 PM Friday 2/14 and 9AM Sat 2/15. E aspect near 6100'.