Avalanche Forecast
Issued: Jan 6th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
rbuhler,
Avalanche Canada
Wind continues to be the main driver of the avalanche danger in the region. The wind direction is expected to shift again on Friday and wind slabs should be expected on all aspects in exposed terrain.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
One more day under the influence of the Arctic high pressure before a storm system moves inland Friday overnight. The south of the region is currently forecast to receive 20-30 cm by Sunday morning while the north will see substantially less.
Thursday Overnight: Cloudy in the south, clear in the north, light variable wind, treeline temperature around -24 °C.
Friday: Cloudy with sunny breaks, light to moderate W wind, treeline high around -22 °C.
Saturday: Snowfall 10-15 cm in the south, less in the north, moderate to strong SW wind, treeline high around -22 °C.
Sunday: Snowfall 10-15 cm overnight, lingering snow flurries in the morning, strong to extreme SW wind, treeline high around -18 °C.
Avalanche Summary
On Wednesday, explosives triggered a size 2 wind slab in the far south of the region. There has been evidence of a few natural wind slabs in the region which occurred at the beginning of the week.Â
Observations have been limited due to the cold conditions. If you are out in the mountains, let us know what you see by filling out a Mountain Information Network report!
Snowpack Summary
Recently formed wind slabs are most likely to be found on south and westerly aspects, but older wind slabs may be found on all aspects. These wind slabs may remain reactive to human triggering for longer than normal due to the presence of weak facets (sugary snow) below them.
The base of the snowpack is composed of crusts and weak faceted grains, particularly in thin snowpack areas. While these layers have generally gone dormant in the region, they still have the possibility of waking up with new snow load or warming, and wind slab avalanches may still have the potential to step down to these deeper layers in isolated areas.Â
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be aware of highly variable recent wind loading patterns.
- The best and safest riding will be on slopes that have soft snow without any slab properties.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Problems
Wind Slabs
Recent strong NE winds have likely formed wind slabs on lee features at treeline and above. These wind slabs are most likely to be found on south and west aspects, but older wind slabs may be found on all aspects.
These wind slabs may remain reactive for longer than normal because they are sitting on weak facets (sugary snow).
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 7th, 2022 4:00PM
