MCS - Pilot Peak east ridge

Quick report

Collapsing

specific

Cold, sheltered areas that formed surface hoar are now buried with the recent storm. This interface is producing signs of instability during skinning and propagating results in snowpack tests. We saw many tracks in and under these areas - did you make good decisions, or did you get lucky? Collapsing felt and whumping heard once reaching north-facing aspects around 7,760 ft.

Weather

Cloud Cover

clear

Clear, sunny day. 30 degrees when we assessed the snowpack (7,700 ft, 13:00), 47 degrees when we finished at Camp Ee Da How (5,570 ft, 15:45). Light winds, gusting moderate.

Snowpack

Snowpack tests around 7,770 ft elevation on north-facing aspects showed failure at the interface between buried surface hoar and storm snow, ranging from appx. 23-30 cm down in total depths of appx. 135-160 cm. The location I assessed in most detail: 136 cm total depth, CT13 SP 23 cm down, ECTP 14 23 cm down. Below that, a layer-cake of rounding facets, melt forms, crusts, and rounds remains.

Avalanche

Size

D1

Aspect

N

Elevation

7710 ft

Unknown trigger: Natural or Skier-remote or Snowmobile-remote; Several skin tracks along the ridge, no downhill ski tracks coming north off the ridge, many snowmobile tracks in the Whoop Um Up Creek flats below. Failed sometime after 02-18 on surface hoar buried with recent storm snow, locally measured in several pits 23-30 cm deep.