Avalanche Forecast

A juicy warm front impacting the coast will bring moderate to heavy snowfall on Sunday, with the potential for blizzard conditions.

Saturday Overnight: Snowing, 5-10 cm of accumulation. Alpine temperatures around -30 C. Southerly winds increasing to strong. 

Sunday: Snowing, 10-20 cm of accumulation. Strong to extreme southerly winds. Alpine temperatures around -25 C.

Monday: Snowing, 2-5 cm accumulation. Moderate to strong southerly winds. Alpine temperatures rising to -10 C.

Tuesday: Light snowfall. Strong southerly winds. Alpine temperatures around -8 C.

Earlier in the week, a natural avalanche cycle occurred in White Pass. This was a result of sustained north winds redistributing the 30-40cm of New Years Eve storm snow. This MIN from Wednesday describes widespread size 2 avalanches, running well into treeline. Avalanches also occurred further inland along the highway corridor on January 4.

Throughout the day, snowfall and strong southerly winds will strip windward areas and form fresh, reactive wind slabs in lee areas. These new wind slabs overlie a heavily wind affected surface of old harder wind slabs and sastrugi. The new snow will probably bond poorly to the old hard surface and human triggering of fresh wind slabs is likely. 

Below the new snow, many days of northerly outflow winds last week formed thick, hard slabs, that overlie a weak faceted (sugary) surface. These older hard slabs will probably be stubborn or unreactive to human triggering, but with limited observations in the past week, we would be treating them with caution. 

• Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
• In times of uncertainty conservative terrain choices are our best defense.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Avoid terrain traps where the consequence of any avalanche could be serious.
• Recent wind has varied in direction so watch for wind slabs on all aspects.