Avalanche Forecast
Issued: Mar 12th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Persistent Slabs and Deep Persistent Slabs.
SH,
Avalanche Canada
20-30cm of snow on Monday will form new slabs, watch locally for their development. The deeper weak layers have not been active in the region this past week but there is uncertainty as to how they will react to the new snow load. There is also the potential for some rain below 1700m Monday afternoon.
Summary
Confidence
Moderate
Avalanche Summary
No avalanches observed or reported over the past 24 hours in Little Yoho.
Snowpack Summary
A sun crust is present on steep solar slopes at treeline and below while 10-30 cm of soft snow can be found on northerly aspects. The various January persistent weak layer interfaces (sun crusts, facets, and surface hoar) are now down 60-120 cm. The weaker Nov. 16 basal facet layer is down 110-170 producing variable but mainly hard to no results in pit tests.
Weather Summary
Monday: 20-30cm at upper elevations with 50km S/SW winds. Freezing levels rise to around 1500m in the afternoon and ridgetop temperatures -5C.
Tuesday: Snow tapering and cooling temperatures throughout the day.
For a more detailed weather forecast click here.
Terrain and Travel Advice
- Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Storm Slabs
Up to 30cm over the next 24 hours in the region with winds will likely form storm slabs on many aspects and elevations. Freezing levels up to 1500m may mean some below treeline slab formation as well. Watch locally for their development.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Three persistent weak layers formed in January are down 60-110 cm. Buried sun crusts found on steep solar slopes present the greatest concern for triggering on these interfaces however weak facets and isolated surface hoar can be found on the same interfaces on shaded aspects. New load may make this layer more reactive.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Weaker facets and depth hoar remain at the bottom of the snowpack in most locations. Be especially cautious in thin snowpack, or rocky areas, where triggering is more likely. Large loads such as cornice failures or smaller avalanches may act as a trigger for this layer so careful consideration of the terrain you travel beneath is wise. Overall we have seen less activity in this region over the past week than further to the East but further load will test that theory.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 13th, 2023 4:00PM
