Avalanche Forecast
Issued: Apr 23rd, 2017 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Deep Persistent Slabs.
aaron beardmore,
Avalanche Canada
The impact from solar radiation will be significant tomorrow. Start early, and finish early.
Summary
Weather Forecast
Clear skies and the potential for intense solar radiation are forecasted on Monday. By Monday evening expect a small system to move through the forecast region with up to 15mm of precip. Wind will remain light with variable direction for the next 3 days. Freezing levels will rise to almost 1900m in the hottest parts of the day.
Snowpack Summary
The snowpack is totally dependent on aspect and elevation now. At treeline and above, melt freeze crusts exist to ridge top on solar aspects, while on north aspects, dry surface snow still exists above ~2400m. Below treeline the snowpack becomes wet during the day and is becoming isothermal. The weak basal facets remain present in alpine areas.
Avalanche Summary
Forecasters received a report of a party of 2 being involved with a size 2 avalanche that was cornice triggered. Both party members were caught and partially buried. They self rescued with minor injuries. A couloir in the Boom Lake area is the best we have for location, aspect elevation etc.
Confidence
Problems
Loose Wet
A limited overnight freeze on Sunday night with some new snow and afternoon warming will create loose wet problems at lower elevations and on S and W facing terrain at higher elevations. Travel early to manage this problem.
- 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.
- Give cornices a wide berth when travelling on or below ridges.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
The snowpack is gaining strength, but the weak basal facets continue to produce sudden collapse results and can produce large avalanches with large triggers or heat. Stick to planar, supported slopes with a deeper snowpack when entering steep terrain
- 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 24th, 2017 4:00PM
