Avalanche Forecast
Issued: Nov 15th, 2021 4:06PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Storm Slabs and Loose Dry.
Ian Jackson,
We are just coming out of the first major storm of the winter. It was a doozy! A warm storm with up to 90 mm of precipitation (water equivalency) - uncommon for the Rockies. Give the new snow time to settle before committing to bigger terrain.
Summary
Weather Forecast
The storm is tapering Monday evening with precipitation stopping, temperatures cooling and winds switching to the NW and decreasing overnight. A ridge is building for Tuesday - Thursday and we will see clear skies, cold temperatures (lows in the -15 to -20 range) and light NW winds.
Snowpack Summary
Up to 70cm of storm snow since Friday with moderate SW winds have created windslabs in the alpine and at treeline and storm slabs at all elevations. This buries a relatively thin, facetted snowpack with a couple crusts in it. Total snow depths are 60-100cm at treeline with more in the alpine. Below 2000m, rain has saturated the snowpack.
Avalanche Summary
Lake Louise ski area reported a widespread natural cycle up to size 2.5 along with a skiier remote size 2 at treeline. Sunshine reported similar with some running as wet loose avalanches at lower elevations. These were a combination of windslab and storm slab avalanches.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
New snow load, wind and warm temps have formed wind slabs, predominantly in the alpine, but also in some treeline areas. These will take a few days to heal following the first major storm of the winter.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
The recent large storm has created widespread touchy storm slabs. We expect this problem to heal quickly with the cooler temperatures, but treat any steep open slopes with caution while the new snow settles.
- Dig down to find and test weak layers before committing to a line.
- Make observations and assess conditions continually as you travel.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Up to 70 cm of recent storm snow is available to run as loose dry avalanches from steep terrain. Watch out for increased sluffing if the wind picks up or changes direction.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 16th, 2021 4:00PM
