Avalanche Forecast
Issued: Mar 23rd, 2017 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
Ian Jackson,
Avalanche Canada
Although natural activity is tapering, the snowpack is still structurally weak and many slopes are ripe for triggering with the right load. Ice climbers should be aware of whether they are exposed to alpine terrain above them
Summary
Weather Forecast
Southwest flow continues with flurries expected on Friday night, possible accumulations of 5-8 cm by Saturday. Seasonal temperatures, expect freezing levels to reach about 1600 meters during the day with treeline temperature from -5 to -8. Winds will remain moderate from the southwest.
Snowpack Summary
100cm of dense, rounded snow comprises the upper half of the snowpack and sits on a variety of different foundations depending on location. In shallow areas (eg: Field ice climbs) the base is weak depth hoar. In deeper areas (eg: Little Yoho Valley), the base is rounded and stronger. Shears persist in the deep facets, and within the storm snow.
Avalanche Summary
Natural avalanche activity has been slowly tapering over the last few days although we have still seen large avalanches running to valley bottom most days! Today, in Little Yoho, there were no new avalanches seen or reported, although a size 2.5 avalanche initiated by a cornice fall was reported near Bow Summit.
Confidence
Problems
Persistent Slabs
Several buried weak layers in the middle and lower parts of the snowpack have been reactive in the last week as they were overloaded by snow and rain. Many large avalanches have run to historical run outs and crossed valley bottom trails.
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
- Be wary of slopes that did not previously avalanche.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Moderate to strong winds SW and W winds over the last 24 hours are adding to the cornices and load on alpine slopes. These fresh windslabs have been touchy in immediate lees and could be the trigger needed for a bigger avalanche.
- If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
- Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2017 4:00PM
