Avalanche Forecast
Issued: Nov 19th, 2019 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
chris gooliaff,
Parks Canada
The Winter Permit System will go into effect Wed, Nov 20. Permits are required to enter restricted areas within Glacier National Park.
Reactive slabs are catching early season travelers by surprise. Choose conservative lines today.
Summary
Weather Forecast
A ridge of high pressure will begin a clearing trend around Rogers Pass for the remainder of the week. A mix of sun and cloud today, with light NE winds, and fzl at 1400m. Wednesday should be sun with clouds, light NW winds, and fzl around 1000m. Thursday will be similar to Wed with a weak inversion bringing warmer alpine temps.
Snowpack Summary
35-50cm of new storm snow overlies an early season snowpack, complete with a series of melt-freeze crusts throughout the height of snow. Mod/strong winds and mild temps have created a persistent slab in alpine and tree-line lee features. These slabs sit upon a crust/surface hoar/stellar layer and are easily triggered by human loading.
Avalanche Summary
Human-triggered avalanches to size 2 were reported from Balu Pass yesterday and the Asulkan Hut area 2 days ago. The Balu Pass avalanche buried the person to their neck and gear was lost. Numerous natural avalanches to size 2.5-3 were observed from Tupper, Macdonald, and Cheops during the storm Sunday morning.
Confidence
Problems
Persistent Slabs
Warm temps, up to 50cm of new snow, and mod/strong SW winds have created a reactive persistent slab. This sits atop a crust/surface hoar/stellar layer, which is an ideal sliding layer for this avalanche problem.
- The new snow will require several days to settle and stabilize.
- Use caution in lee areas. Recent wind loading has created wind slabs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 20th, 2019 8:00AM
