Avalanche Forecast

Issued: Mar 26th, 2017 8:10AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Wind Slabs, Persistent Slabs and Loose Wet.

ian gale, Parks Canada

Glacier.

We're starting to transition to a spring snowpack. Solar and daytime heating will increase avalanche hazard. Avoid South and West aspects when the effects of the sun are strong!

Summary

Weather Forecast

A low pressure system moving inland from the coast today will displace the ridge of high pressure currently sitting over the Southeastern BC. This morning will remain clear with cloud building in the afternoon and potential for convective flurries. Winds will be in the 10 -30km/hr range from the S and freezing level will go up to 1600m.

Snowpack Summary

South winds and 20-30 cm of snow in the last 24 hrs have built variable soft slabs in the alpine and exposed treeline areas. Below 1900m, 20-30cm sits on a supportive crust, this new snow became moist in the afternoon yesterday and was reactive. Persistent layers exists down 150cm (February crust) and near the base of the snowpack (November crust).

Avalanche Summary

We experienced a natural avalanche cycle in the park yesterday to size 3. These were triggered by rapid loading from convective flurries, steady winds and warm temps. Field teams in the Asulkan area found a moist slab below 1900m. This slab was touchy where it was sitting on a crust and produced loose wet avalanches to sz 2 with heavy debris.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

Moderate winds and 10-15 cm of new snow have formed isolated wind slabs on lee features in the alpine. Wind slabs may be poorly bonded to last week's storm snow and may step down to deeper layers if triggered.

Use caution in lee areas. Recent wind loading has created wind slabs.Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

The month of March has been characterized by heavy loading of new snow and rain. After an intense avalanche cycle, the snow pack is still stabilizing. Deep weak layers have been failing sporadically leading to large avalanches.

Choose regroup spots that are out of avalanche terrain.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Loose Wet

Spring is here! With daytime or solar warming the upper snowpack is becoming moist in the afternoon. This moist slab is touchy below 1900m where a crust down 30 is providing a good bed surface for wet avalanches.

Travel early before the heat of the day, and avoid big slopes in the afternoon.Cornices become weak with daytime heating, so travel early on exposed slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 27th, 2017 8:00AM