Avalanche Forecast
Issued: Apr 19th, 2017 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Persistent Slabs.
ian jackson,
Avalanche Canada
Isolated windslabs exist at ridgetop on north and east aspects in the alpine but are generally small and predictable. Start and finish your trips early before the strong April sun destabilizes the snowpack.
Summary
Weather Forecast
Thursday looks to be partly cloudy with some afternoon flurries and freezing levels rising to ~ 2400m. Friday morning there will be a weak freeze, but sunny skies will make afternoon temperatures even warmer. Saturday looks to be the warmest day as we start to finally get into a springlike pattern. Winds look to be light through the period.
Snowpack Summary
The snowpack is a real mixed bag right now: totally dependent on aspect and elevation. At treeline and above, melt freeze crusts exist to ridgetop on solar aspects, while on north aspects, dry surface snow still exists above ~2200m. Below treeline the snowpack becomes wet through the day. The snowpack is slowly transitioning to a spring snowpack.
Avalanche Summary
Two size 3's were reported in the Sunshine Village backcountry. These were both initiated by cornice failures in the alpine at ~2800m which triggered the deep persistent weak layer and failed on the ground.
Confidence
Problems
Loose Wet
Afternoon warming will create loose wet problems at low elevations and on S and W facing terrain at higher elevations.
- Pay attention to sluffing off cliffs and steep solar terrain, signs of a warming snowpack.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices continue to fail. Minimize your time underneath these and remember that a cornice failure could also trigger the deep persistent slab on the basal facets.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
- Give cornices a wide berth when travelling on or below ridges.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
The snowpack is gaining strength, however the facets deeper in the snowpack remain a concern in thin alpine areas and where a cornice could trigger the slope.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 20th, 2017 4:00PM
