Sea to Sky Avalanche Forecast

Issued: Jan 14th, 2022 4:00PM

Sat Jan 15th Current Conditions
Alpine Moderate Treeline Low Below Treeline Low
Sun Jan 16th 2 Day Outlook
Alpine Moderate Treeline Low Below Treeline Low
Mon Jan 17th 3 Day Outlook
Alpine Moderate Treeline Low Below Treeline Low

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs.

If you head high into the mountains to search for dry snow, watch for pockets of wind slab that are still possible to trigger. At lower elevations a thick surface crust reduces the likelihood of avalanche activity.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength. We have a good understanding of the snowpack structure and confidence in the weather forecast

Weather Forecast

Unsettled conditions and shifting freezing levels remain until Monday, when the next front approaches bringing light snow to the Coast.

FRIDAY NIGHT: Cloudy with light snowfall, up to 5 cm. Strong southwest winds. Freezing levels sit below 1500 m. 

SATURDAY: Cloudy with a chance of flurries. Freezing levels stay below 1000 m. Strong westerly winds. Alpine high -2.

SUNDAY: Mostly cloudy with a chance of flurries. Strong westerly winds. Freezing levels around 1500 m. Alpine high -1.

MONDAY: Light snowfall begins, with up to 5cm over the day. Freezing levels around 1500 m. Moderate southwest winds. Alpine high -1. 

Avalanche Summary

Recent heavy precipitation and warm temperatures produced widespread natural avalanche cycles at all elevations. At treeline and below saw wet loose and slab avalanche cycles to size 3 on all aspects, during the most intense rain and warming. Upper treeline and alpine terrain produced storm slabs to size 3 in most areas. 

Several very large avalanches have been noted since the storm, up to size 4 where terrain allows. Of note, an avalanche was naturally triggered near Harrison Lake, in the South Coast region. This was thought to have started as a cornice fall which triggered a large storm slab and stepped down to a deeper layer. It likely failed on the weak early December facets as it was up to 3 m deep in places and ran approximately 1300 m.

Snowpack Summary

Heavy precipitation over the last week has created a variety of surface snow conditions. Strong southwest winds have created pockets of dry snow at alpine elevations on north through east facing slopes. Precipitation fell as wet snow or rain below 2200m, creating saturated snow that is forming a melt freeze crust with moist snow below. 

A crust that formed prior to the rain was observed up to 2000m. This is now buried up to 30 cm deep and may be breaking down at lower elevations.

Two buried weak layers of sugary, faceted grains sit in the middle and lower snowpack, at 100cm deep and 150-250 cm deep. The deeper layer was formed by heavy rain followed by a cold spell in early December. It is most prominent between 1700 and 2100 m. Avalanches on this layer are large, but sporadic and isolated. The most likely place to trigger it would be in thin, rocky snowpack areas. 

The lower snowpack is well-settled and strong.

Terrain and Travel

  • Be alert to conditions that change with elevation and wind exposure.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Make observations and assess conditions continually as you travel.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1.5 - 2.5

Pockets of wind affected snow from the strong south-southwest winds may still be reactive to a human trigger. Take care around wind loaded ridgelines and cross loaded features mid slope. 

Aspects:

North, North East, East, South East, West, North West.

Elevations:

Alpine.

Valid until: Jan 15th, 2022 4:00PM

Forecast Trend

The latest forecast danger ratings, broken down to elevation. See how an elevation is trending.