Avalanche Forecast
Issued: Feb 28th, 2020 8:33AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
mike smallwood,
Parks Canada
The snow load over the February 22nd surface hoar is increasing and priming for a trigger
Summary
Weather Forecast
5cm today, wind light south. Freezing levels could rise to 2000m before dropping this afternoon with a period of intense precip. Tonight 10cm with falling temperatures and winds picking up to strong from the west. Periods of convective snowfall through the day tomorrow, freezing level falling to 1000m and winds dropping off to light, west.
Snowpack Summary
A widespread 3-7mm surface hoar layer on all aspects in combination with a 2-4cm sun crust was buried on February 22nd and now has up to 50cm of storm snow above it. This layer has been observed to 2450m. No other layers are currently active in the 3.5m snowpack of mostly rounded grains.
Avalanche Summary
A field team ski cut predictable small convexities yesterday with isolated results to sz 1 on the Feb 22nd surface hoar. Numerous reports of skier-triggered avalanches on the February 22nd layer to sz 1.5 this week. More snow and rising temperatures today will likely overload this weak layer causing natural avalanches on all aspects.
Confidence
Problems
Persistent Slabs
Feb 22 surface hoar is a persistent weak layer down 50-60cm that overlies a thick crust on solar aspects. Use extra caution on slopes that have not seen any activity since this layer was buried
- Use caution on open slopes and convex rolls where buried surface hoar may be preserved.
- Be aware of the potential for larger avalanches due to a buried surface hoar layer
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
20cm overnight on the 27th has formed fresh storm slab. More snow and warm temperatures today will promote slab formation and sensitivity to triggering
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Choose well supported terrain without convexities.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 29th, 2020 8:00AM
