Avalanche Forecast
Regions: Little Yoho.
There is uncertainty around how likely it will be to trigger large avalanches on the persistent weak layers in this region.
Conservative decision making is recommended.
Confidence
Moderate
Avalanche Summary
No new natural avalanches observed in Little Yoho on Wednesday, avalanche control on Mount Cathedral (proximate to the region) produced avalanches up to size 3.
A group digging a snowpit in low angle terrain with no overhead exposure on Observation Peak March 18th felt a whumph that remote triggered 5-6 avalanches up to size 2.5 in the cirque around them. This remote trigger with large propagation highlights the dangerous snowpack conditions we are currently in.
Snowpack Summary
At treeline, ~70-100cm of snow overlies the Jan. 30th / Feb. 22nd drought layers. This layer is ~ 20-30 cm of facetted crystals that are weaker than the snowpack above and have been reactive in snowpack tests and with avalanches in the last 10 days. Average snowpack depths at treeline are ~ 200cm.
Expect a surface crust on solar aspects treeline and below.
Weather Summary
Wednesday night: Mainly cloudy with isolated flurries. Alpine temps: Low -8 °C. Mostly light ridge wind occasionally gusting to 35 km/h
Thursday: Cloudy with sunny periods and isolated flurries. Alpine temps: High -4 °C. Ridge wind west: 15 km/h gusting to 50 km/h. Freezing level: 1700 metres
Friday: Flurries. Accumulation: 8 cm. Alpine temps: Low -9 °C, High -5 °C. Ridge wind southwest: 15 km/h gusting to 50 km/h
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Loose avalanches may step down to deeper layers, resulting in larger avalanches.
- Wind slabs are isolated, but may remain reactive.
Avalanche Problems
Persistent Slabs
A 60-100 cm slab overlies mid-pack facets. We have limited observations from this zone since the storm, but this layer seems less reactive in Little Yoho than in areas further east. Caution is advised as this layer needs time to stabilize: avoid start zones and be very wary of overhead hazard.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3.5