Avalanche

White Pass Backcountry from 5500 - 6500'

Josh LipkowitzWest Slopes South
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Quick report

Breakable crust and rain runnels made for challenging travel, but minimal avalanche concerns. The multiple rain events have led to a relatively homogenous snowpack of strong rounds and melt forms up until at least 6600'. Limited observations from the upper elevations make it impossible to rule out an isolated wind slab pocket in locations that stayed snow during the last storm. 

We were surprised today at just how soft the snow surface was on a southeast aspect at 6300'. The moist surface, and what appeared to be fresh roller balls, point to a possibility of wet loose activity on steep mid and upper-elevation southerly aspects. 

Weather

Air Temp
23
Cloud Cover
scattered
Wind Loading
none
Recent Snowfall
0
Snow Avail For Transport
none

Crisp and cold in AM. Overcast at pass elevation, with clearing skies above the cloud deck at approximately 5500'. Light and variable winds along our route.

Snowpack

A 2" breakable melt-freeze crust was present throughout our tour, with the notable exception of a southeast aspect at 6300' where the snow surface was soft, moist, and what appeared to be fresh roller balls were present. In addition to the challenge of the breakable crust, rain runnels were abundant up until at least 6700'.

Our flat field snow profile at 5800' had a snow depth of 33 in (HS: 85cm). Below the surface melt-freeze crust was approximately 10" of dry snow from the recent storms sitting atop the 12/6 interface. Below the 12/6 interface, the snow was moist and consisted of a combination of melt forms and decomposing crusts.

Potentially of future note, we observed fairly wide-spread and well-developed surface hoar (2-8 mm depending on location) in sheltered areas. 

Avalanche

Size
D1.5
Type
WL
Count
2
Aspect
NE
Trigger
N
Elevation
6300 ft

We observed several debris piles from wet loose avalanches from the last atmospheric river event. The Gunsight Peak avalanches were the same as those noted on the 12/11 observation where visibility was limited.