Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Mt. Bosworth avalanche closure zone is CLOSED on Thursday, January 16th.
High elevation winds have been strong to extreme for the last week, so be on the lookout for windslabs if venturing into high, windy spots.
Deep slabs haven't been observed in days, but a weak snowpack persists in shallow areas - ski the thick, avoid the thin.
Confidence
Moderate
Avalanche Summary
One size 1.5 windslab was reported today, 30-50 cm deep on Bow Peak, SE aspect, in the alpine. It looks like it occurred within the past 48 hrs, and was downslope from the ridge crest, perhaps a result of the strong winds loading lower on the lee slope. Otherwise, no new avalanches were reported in the past 2 days.
Snowpack Summary
Last week's 10cm accumulated snow and strong to extreme west winds created slabs in exposed high alpine areas. The recent snow rests on a layer of facets and surface hoar, although we haven't seen many avalanches sliding on this layer yet. The middle and bottom of the snowpack are weak, with depth hoar and facets near the ground. An average of 60-100cm of snow can be found at treeline elevations.
Weather Summary
Thursday, we expect extreme SW winds accompanied by up to 5 cm new snow.
On Friday, we will see cooling temperatures and easing winds as arctic air moves in for the weekend.
Terrain and Travel Advice
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
Recent snow and extreme NW to SW wind have developed small slabs in high alpine terrain that is exposed to the wind. These may run further than expected if they pick up facetted snow in steep gullied terrain.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2
Deep Persistent Slabs
Weak facets exist at the base of the snowpack. Although we haven't seen much avalanche activity on this layer in a while, the snowpack structure is weak and large open slopes at treeline and in the alpine remain suspect.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1.5 - 2.5