Avalanche Forecast
Issued: Jan 30th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
ldreier,
Avalanche Canada
Moderate southerly wind will redistribute the new snow and create fresh wind slabs in lee terrain features in the alpine and at exposed treeline. Older wind slabs built by easterly and northerly outflow winds might still be reactive and harder to recognize.
Summary
Confidence
Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.
Weather Forecast
SATURDAY NIGHT: Cloudy with clear periods, up to 5 cm new snow, moderate southeast wind, treeline temperature -8 C.
SUNDAY: Mainly cloudy with scattered flurries, up to 5 cm new snow, moderate south wind, treeline temperature -6 C.
MONDAY: Mix of sun and cloud, 3 cm new snow, moderate southwest wind, treeline temperature -8 C.
TUESDAY: Mainly cloudy, 10-15 cm new snow, moderate southwest wind, treeline temperature -8 C.
Avalanche Summary
On Friday, several wind slab avalanches were triggered by skiers on southerly aspects (see this MIN report). Wind slab avalanches up to size 2 were triggered with explosives in the north of the region. A few wind slab avalanches up to size 2 released naturally in the alpine on westerly aspects on Thursday. These wind slabs were likely formed by the northerly and easterly outflow winds on previous days. Recent glide snow avalanche activity was reported on Wednesday.Â
Snowpack Summary
10-35 cm of recent snow sits on a crust below 1000 m and surface hoar in sheltered locations at and below treeline. The layers in the mid and base of the snowpack have gained strength with high snowfall amounts in January. Deeper layers appear to have gone inactive in the southern part of the region. However, in the northern part of the region (e.g. Bear Pass, Ningunsaw) there has still been regular avalanche activity on weak snow at the bottom of the snowpack with large loads such as explosives or cornice collapses.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Watch your sluff: it may run faster and further than you expect.
Problems
Wind Slabs
Moderate southerly wind is forecast overnight and during the day. Where winds reach upward of 20 km/h they will redistribute the new snow and build fresh wind slabs in lee terrain features in the alpine and exposed treeline. Older wind slabs were formed on westerly aspects and may still be reactive. Wind slabs will be particularly reactive anywhere snow overlies buried surface hoar or crust. The surface hoar layer is likely preserved in sheltered areas at treeline elevations and below treeline.
In steep and wind-protected areas loose snow avalanches (sluffs) are expected.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 31st, 2021 4:00PM
