Avalanche Forecast

Issued: Feb 17th, 2015 8:00AM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet, Cornices and Persistent Slabs.

ali haeri, Parks Canada

Glacier.

Summary

Weather Forecast

High pressure ridge still dominates over our region. Clear skies and dry conditions to persist until Thursday when a weak system approaches the Interior delivering cloud and light snow into Friday.

Snowpack Summary

5-15cm of light snow, wind effected in open areas, overtop the Feb 14 crust above 1700m. Crust was observed to be ~10cm thick to 2200m. The Jan 30 crust layer is down ~1-1.25m which formed a crust to 2200m. Jan 15 surface hoar layer is down ~1-1.5m. The mid and lower snowpack is well settled. Nov 9 basal crust layer still present in the alpine.

Avalanche Summary

2 solar induced avalanches yesterday to size 2.5 within the highway corridor. From Feb 14, 2 impressive deep slab avalanches, one a size 3.5, running on glacier ice from the slope between Clark peak and Mt Swanzy, North aspect visible from Loop Brook, and in the Asulkan Valley, East aspect, size 3.0 from Mt Pollux running on the ground/Nov 9 crust.

Confidence

Due to the number and quality of field observations

Problems

Loose Wet

5-15cm of snow over a firm surface can be released as loose avalanches with solar effect. Solar radiation today will be strong with clear skies.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Large cornices throughout the Park will be getting more solar radiation today. Manage your groups exposure to this overhead hazard even on shaded slopes as the cornices above are still in the sun.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

We have persistent weak layers down between ~1 to 1.5m. A large load such as a cornice failure will be needed to trigger these layers. Alternatively humans may be able to trigger them from shallow areas.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Feb 18th, 2015 8:00AM