Avalanche Forecast
Issued: Dec 9th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Storm Slabs and Persistent Slabs.
JH,
Avalanche Canada
~45cm of low-density storm snow is making for some quality skiing and riding! Don't let the powdery conditions obscure your avalanche awareness.
Fresh slabs will remain reactive through the weekend. Adding to that, the weak layer from Nov. 17th persists as a major concern in isolated areas that have not seen previous heavy traffic or avalanche activity. If you don't know the history of a steep open slope, leave it for another time.
Summary
Confidence
Moderate
Avalanche Summary
On Friday, there was a cycle of loose dry avalanches, up to size 2 from the steep terrain in the Eastern highway corridor, and one size 3.0 storm slab from MacDonald gully number 9.
On Thursday, a field team triggered a small storm slab on a small slope, from an E aspect at treeline.
Snowpack Summary
Up to 45cm of low-density storm snow will form slabs quickly as the winds increase. This new snow sits on a slippery layer from Dec 5th, consisting of surface hoar, preserved stellars, facets and a thin suncrust.
The Nov 17th Surface Hoar is now buried 60-90cm below the surface. This layer continues to produce tree rattling whumpfs, as well as sudden snowpack test results, in untravelled clearings at and just below treeline.
Weather Summary
Saturday will be mainly cloudy with flurries, moderate to strong South wind at ridge top, an alpine high of -6*C, and freezing levels up to 1300m.
Sunday will be similar, with light winds and a few more sunny breaks as a ridge of high pressure sets up over the area.
Next week will start with a stable weather pattern - sunny periods, light winds, and seasonal temps.
Terrain and Travel Advice
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Wind Slabs
30-40cm of low density new snow will build fresh slabs quickly with any input from the wind. With a forecast of moderate to strong South winds for Saturday morning, you can expect reactive slabs to be forming in exposed terrain at upper elevations.
Aspects: North, North East, East, South East, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Approximately 45cm of dry, low-density snow has fallen this week. This snow sits on a slippery Dec. 5th interface and may become more reactive as it settles in to a slab with incremental snowfalls, warming temps, and wind.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Persistent Slabs
The Nov 17 surface hoar is down 60-90cm and most prevalent around tree line. This layer of large surface hoar continues to give 'sudden' results in snowpack tests, and produce dramatic whumfs in previously untraveled open glades.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Dec 10th, 2022 4:00PM
