Cold pow in N facing terrain, solar triggered avalanches on S aspects

Map for Mountain Information Network report: Cold pow in N facing terrain, solar triggered avalanches on S aspects

Snow conditions

Riding quality was:
Amazing
Snow conditions were:
  • Deep powder
We rode:
  • Alpine slopes
  • Open trees
We stayed away from:
  • Sunny slopes

Information

The day was:
  • Sunny
  • Warm
Avalanche conditions
  • Slab avalanches today or yesterday.
  • 30cm + of new snow, or significant drifting, or rain in the last 48 hours.
  • Rapid temperature rise to near or above 0°C or wet surface snow.

Comments

-19C at 8 AM in the parking lot rapidly warmed to near -5C at the valley bottom. South-facing slopes reacted to the warming and the first intense solar input of the year by producing several large avalanches (up to size 2.5). Winds were light today but the recent wind effect was evident in the alpine. We saw several recent windslab and cornice avalanches in north-facing terrain and encountered isolated pockets of soft windslab at treeline. In sheltered features, ski/sled penetration was between 40-50cm with roughly 20-30cm of low-density new snow sitting on facets. We managed the hazard by avoiding any exposure to overhead south-facing avalanche paths even when that meant battling through tight trees on the sleds and choosing sheltered north-facing terrain to ski.