Avalanche Forecast
Regions: Little Yoho.
Recent winds and up to 10 cm of new snow have changed conditions. Watch out for windslabs in alpine and treeline locations.
We have noticed some small avalanches running further than expected recently as they gather facetted snow in the track.
Confidence
Moderate
Avalanche Summary
Minimal observations from Little Yoho, but in the neighboring BYK region:
Local ski hills were reporting small windslabs 10-15 cm deep that were failing with explosives in alpine and isolated treeline terrain.
In Yoho, a natural size 2 ran to the bottom of the runout in one of the avalanche paths between Carlsberg and Guinness.
Snowpack Summary
5-10cm of new snow has been blown into windslabs in the alpine and at treeline. This sits on a layer of facets and surface hoar that may or may not become a bad sliding surface. Below this, the mid-pack is generally strong but a weak crust/facet layer can be found near the ground in shallow snowpack areas. At treeline, average snowpack depths are 120-150 cm. The snowpack here is generally deeper and more consolidated than areas further east in the BYK region.
Weather Summary
We are in a period of active weather, although not much snow is forecast. Thursday should be mostly sunny with moderate to strong NW ridgetop winds. Friday into Saturday we should see a few centimetres of snow with extreme SW winds diminishing throughout the day on Friday. Temperatures will remain cool throughout the period.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Avalanche Problems
Wind Slabs
5-10 cm of new snow with strong westerly winds have created windslabs in alpine and isolated treeline areas. We suspect these are small in most areas, but a size 2 natural was observed on Mt. Dennis in Field that may have initiated as a windslab.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Deep Persistent Slabs
The deep persistent problem has been less reactive in Little Yoho than in thinner areas to the east. However, weak facets still exist in thin snowpack areas (windblown ridges and cross-loaded gullies) so exercise caution if travelling through these areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 1.5 - 3