Avalanche Forecast
Issued: Mar 1st, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
Chris Gooliaff,
As we transition out of stormy weather, use a cautious approach to gain knowledge on the upper snowpack and how it is bonding with the underlying base.
Summary
Weather Forecast
The Kootenay/Boundary region and Washington took the brunt of this storm, leaving us with unsettled flurries and gusty SW winds
Tonight: Flurries, 5cm, Alp low -5*C, gusty strong SW winds
Wed: Cloudy, isolated flurries, Alp high -4*C, FZL 1700m, light to mod gusty SW winds
Thurs: Cloud and sun, flurries, Alp high -6*C, FZL 1500m, light NE winds
Snowpack Summary
30-35cm of storm snow overlies a facet layer, small surface hoar in sheltered areas Treeline and below, and a sun crust on steep solar aspects. The Feb 15 surface hoar/sun crust is down 50-80cm and may become active with the new load, warming temps, and wind transport. Plenty of loose, dry snow up high for wind redistribution.
Avalanche Summary
A natural cycle in the highway corridor Tues afternoon, with numerous paths (Tractor Shed W, Crossover, Mac #7,10, Lens) to the east spitting out sz 2.5 to 3's. Avalanche Crest had numerous low-elevation slabs with the warming.
A skier triggered sz 2 in the Connaught Path Sunday shows the new snow is not yet bonded to the underlying bed surface.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
Storm Slabs
Storm slabs buried a mix of surfaces; small surface hoar around Treeline and below, sun crust on steep solar aspects, facets and firm wind slab elsewhere. S'ly aspects with sun crusts and low elevation unsupported rolls may be more sensitive.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas in the alpine and treeline. Recent storm snow has formed slabs.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A persistent weak layer of surface hoar and/or sun crust sits 50-80cm down, depending on wind loading and aspect. As temps rise and snowload increases, this layer may become reactive in areas where it has not previously slid.
- If triggered the storm slabs may step down to deeper layers resulting in larger avalanches.
- Persistent slabs may be more sensitive to human triggering on solar asp where they sit on sun crust
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: Mar 2nd, 2022 4:00PM
