Sea To Sky

Danger could rise sooner than indicated if we see more than 10 cm of new snow (with wind) before the end of the day on Wednesday.

Moderate

WEDNESDAY: Mainly cloudy with snow developing late in the day. The freezing level should be around 1500 but will rise to 1800 m overnight. Ridge winds increase to strong or extreme from the SW-SE with the arrival of the storm. THURSDAY: Periods of snow – 40-70 cm Wednesday night through Thursday. The freezing level drops to around 1400 m and winds are moderate to strong from the south. FRIDAY: Cloudy with sunny breaks. The freezing level could rise to 1800 m during the day and winds ease to light.

We've had reports of skier and explosive controlled avalanches up to size 2 (mostly size 1-1.5) each day for the past few days. Most of these have involved only the most recent snowfall (~24 hours) and were limited to steep wind-loaded slopes. On Sunday a loose dry sluff triggered a size 3 wet slab at 1400 m. This slide released on the mid-Feb crust. On Saturday there was evidence of widespread natural storm slab avalanche activity to size 3.5. The avalanches failed in response to heavy storm loading on Friday and possibly warming on Saturday.

Storm totals from the past week were well over 100cm with more currently falling and much more on the way. Previous strong S-SW winds have shifted the new snow into deeper slabs on lee and cross-loaded alpine and treeline features. With the exception of shady alpine slopes, 30-50 cm of storm snow overlies a melt-freeze crust that formed on Sunday from high freezing levels and sun. Ongoing stormy weather has also encouraged extensive cornice growth. Weaknesses below the recent storm snow are expected to have gained considerable strength while the mid and lower snowpack are also strong and well-settled.