Avalanche Forecast
Issued: Mar 5th, 2020 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
chris gooliaff,
Parks Canada
It's a good time to use caution in the backcountry. We've been spoilt this winter with few concerns from persistent weak layers. This has now changed, with the Feb 22 surface hoar/suncrust layer lurking at a depth that can be triggered by people.
Summary
Weather Forecast
Rising temps today with snow arriving tonight.
Today: Mainly cloudy, flurries, Alpine high -5*C, fzl rising to 1600m, light/mod W winds
Tonight: 10-15cm, Alpine high -5*C, mod/gusting strong SW winds
Fri: Cloudy with sunny periods, trace snow, Alpine high -5*C, light/gusting strong W winds, fzl 1300m
Sat: Cloudy, 5cm, Alpine high -9*C, light W winds
Snowpack Summary
Surface windslabs in open terrain features at all elevations. Some alpine bowls have been blasted by the winds while others appear barely touched. Wind effect is variable. Below these slabs, the Feb 22nd persistent weak layer is now buried down 60-70cm, and consists of 3-7mm surface hoar on all aspects up to 2450m, and a crust on solar aspects.
Avalanche Summary
Natural activity died down during the day yesterday after Tues night's spike in natural avalanches. Below tree-line in the Connaught drainage, a skier triggered sz 1, 40cm deep was reported. Just west of the park at an elevation of 2000m, there was a report of a skier-controlled sz 1.5 on surface hoar, down 55-70cm, on terrain as low as 10*.
Confidence
Problems
Wind Slabs
Windslabs in open terrain features on all aspects in the Alpine and exposed areas of TL and BTL. If triggered these wind slabs have the potential to step down to the Feb 22nd surface hoar layer.
- Be aware of the potential for wide propagations due to the presence of hard windslabs.
- Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Feb 22nd SH is now buried 60+cm deep, which is a likely depth for skier triggering, especially in shallower snow pack areas. Steep solar aspects harbor a crust under the surface hoar layer, which can increase the sensitivity of triggering.
- If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
- Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 6th, 2020 8:00AM
