Valanga

Driving Hailey to Stanley and back

Scott SavageSawtooth & Western Smoky Mtns
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Quick report

On a late afternoon/early evening glassing mission from Hailey to Stanley, several large (D2) and countless (50-100?) small (D1) avalanches were observed. These natural slab avalanches released at or near ridgelines, in obviously wind-loaded areas, on mostly E and SE aspects, and mostly in upper elevation terrain. Many of the slides appeared to start as very thin wind slabs or cornce fall and then entrained snow, ultimately resembling loose snow avalanches. 

Weather

Air Temp
Low 20s at pass level
Cloud Cover
few
Wind Loading
previous
Recent Snowfall
10-15cm
Snow Avail For Transport
small smounts

Wind was the big story: intense previous wind transport, and strong W-NW winds were still moving snow at all elevations at 4 PM, on alpine ridges in the Boulder Mtns at 6:30PM. By this evening, there was little snow that was still easily transportable.

Snowpack

Extensive wind affects in upper and middle elevation terrain. The wind appeared to be blowing hard enough that, while wind slabs formed, a lot of the wind-transported snow formed dunes and ripples and sublimated ("dissappeared" into thin air). Cornices obviously grew today.

Surfaces on many W-SW-S aspects were shiny and glazed by Sat evening. 

Avalanche

Size
D2
Count
3
Aspect
E
Trigger
N
Elevation
9400 ft

A handful of D2 wind slab avalanches released at or near ridgelines, mainly in the Sawtooths and western Smoky Mtns. There was evidence of dozens of smaller D1 avalanches, and the wind had undoubtedly erased evidence of many more. Activity was clearly focused on E-SE aspects.