Avalanche Forecast
Issued: Feb 20th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
JA,
Avalanche Canada
New snow and a change to northeasterly winds will create new wind slabs at ridge crest on southerly aspects. We are expecting continued natural wind slab and deep persistent slab avalanche activity.When assessing your ski objectives, look for overhead hazards such as large alpine bowls, cornices, or cross loaded slopes. Choose terrain conservatively and bear in mind the potential for a low probability high consequence avalanche occurrence.
Summary
Confidence
Moderate
Avalanche Summary
Parkway patrol on Sunday observed isolated large natural deep persistent slab avalanches up to size 2.5 in the alpine - 2 had stepped down to the basal facets.
Late report from Shangrila area of a large avalanche off Mnt Jeffrey reaching the creek likely on Feb 16.
Don't forget to post avalanche observations to the MIN.
Snowpack Summary
New snow from overnight Monday will be sitting on wind slabs in the alpine and exposed tree line formed by recent strong to extreme southwesterly winds. In sheltered locations the upper snowpack is comprised of 30cm settled snow from the past couple of weeks on top of a generally weak mid and lower snowpack with facets and depth hoar at the base. The height of snow is variable from 50 to 150cm.
Weather Summary
We are expecting up to 15cm new snow by Tuesday morning throughout the bulletin region. The Arctic airmass will descend and push the active low pressure to the south on Tuesday. Winds will be light overnight switching to moderate values from the northeast in the morning. Temperatures will plummet below seasonal values with isolated flurries continuing into Wednesday.
Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast
Terrain and Travel Advice
- Expect slab conditions to change drastically as you move into wind exposed terrain.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
With the new snow and a switch to northeasterly winds expect slab development on non typical lees. These wind slabs will have a potential to overload the deep persistent layer below and result in larger than expected avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Natural avalanches continue to step down to this layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 21st, 2023 4:00PM
