Avalanche Forecast
Regions: Little Yoho.
While the recent wind effect may become obscured with incoming snow Saturday evening and Monday, expect furthrer windslab and cornice development to keep alpine and treeline hazard elevated into the middle of the week.
Weather Forecast
Following freezing levels near 2000m and a warm, gusty, wave of precip Saturday evening, temperatures should drop overnight with freezing levels only reaching 1400m for Sunday under a weak, dirty ridge. Up to 10cm is expected to arrive with moderate winds at treeline Monday however with a 1400m freezing level, rain is possible at valley bottom.
Snowpack Summary
Widespread wind effect treeline and above with 20 to 35 cm of new snow sitting on a well settled mid and lower pack. This new snow overlies a temperature crust below 1800m on polar aspects and a sun crust into the alpine on solar aspects. No significant shears found in the mid and lower pack, however thin snowpack areas are still suspect.
Avalanche Summary
Numerous loose wet slides up to size 2 out of steep terrain below treeline in Little Yoho with limited activity at higher elevations. Numerous natural avalanches observed in the Alpine on the 93N on 93S up to size 3 all aspects following the storm on Thursday. Most of this was triggered by wind loading with failures on crusts and the deep facets.
Confidence
Freezing levels are uncertain on Monday
Avalanche Problems
Wind Slabs
Recent SW winds have formed wind slabs and encouraged cornice development. Watch for changes in the surface of the snow that indicate wind slabs, and look for clues like cracking. Use conservative terrain selection where wind effect is found.
- The new snow will require several days to settle and stabilize.
- Be cautious as you transition into wind affected terrain.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
The persistent weak layers from January and February are bonding well, and have a low likelihood of triggering in most of this forecast area. Overall the snowpack is quite strong, but continue to be wary of shallow snowpack areas with more facetting.
- Carefully evaluate and use caution around thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3