Avalanche Forecast
Issued: Dec 20th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Persistent Slabs.
Chris Gooliaff,
Great skiing abounds in the Pass! As the temps drop, toss some extra warm clothing into your pack. And why not a headlamp? Dec 21 is the shortest day of our winter!
Keep an eye out for wind slabs at ridge-top or on unsupported features.
Summary
Weather Forecast
A mixed weather Tues, a stormy Wed/Thurs, then an extended period of cold weather.
Tonight: Clear, Alpine high -16*C, light SW winds
Tues: Mix of sun/cloud, Alpine high -8*C, light SW winds
Wed: Snow, 25cm, Alpine high -8*C, mod/gusting strong SW winds
Thurs: Flurries, 6cm, Alpine high -6*C, light/gusting mod W winds
Snowpack Summary
Excellent snow quality can be found throughout the Park with 40cm of new snow from the weekend storm. The Dec 1 crust is ~10cm thick, buried 50-100cm deep, and can be found at elevations up to 2300m. Facets (loose, sugary crystals) have been found above and below this crust, particularly in shallow snowpack areas, at and just below tree line.
Avalanche Summary
No natural avalanche activity was observed by highway patrol nor by a field team in the Lookout/Ravens area.
Snowpack tests continue to give sporadic sudden results on the Dec 1 crust, particularly in shallower snowpack areas at tree line.
Confidence
Problems
Wind Slabs
Moderate S'ly winds may have redistributed the recent 40cm of new snow into pockets of slabs on lee features and in cross loaded areas at or near ridge line. Watch for a change from soft to hard snow, these are the slabs you are trying to avoid.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
The surface snow is faceting and running like sugar down a cake. Getting pulled into a terrain trap by your sluff wouldn't be sweet, though, so watch where the loose snow is flowing as you make your ski cut.
- Be careful of loose dry power sluffing in steep, confined or exposed terrain.
- Use caution above cliffs and terrain traps where small slab avalanches may have severe consequences.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Dec 1st crust is buried by ~100 cm of snow and is of most concern in shallow, windward areas around tree-line. It seems to be unreactive at the moment, but with increasing load it could wake up.
- Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 21st, 2021 4:00PM
