Avalanche Forecast
Issued: Feb 5th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Wind Slabs.
swerner,
Avalanche Canada
Fresh storm slabs may be touchy and reactive on Saturday, especially to skier and rider triggering. Snowfall amounts are uncertain so if you see more than 25 cm in your local riding area the avalanche hazard is HIGH.
Summary
Confidence
Weather Forecast
A series of upper disturbances are expected as the arctic front pushes West of the Divide bringing localized periods of snow to the region. It's hard to pin-point snowfall amounts and they may be heavier than what the models suggest.
Overnight Saturday: Light snow 5-10 cm. Ridgetop wind mostly light with strong gusts from the northwest. Alpine temperatures near -12.
Saturday: Snow amounts 5-15 cm. Ridgetop wind moderate from the East. Alpine temperatures -12.
Sunday: Mix of sun and cloud with some flurries. Ridgetop wind light from the East and alpine temperatures dipping to -25.
Monday: Mix of sun and cloud. Ridgetop wind light from the East and temperatures -25.
Avalanche Summary
No recent reports on Friday. On Wednesday, numerous loose-dry natural avalanches were reported up to size 1.
With forecast strong wind, fresh wind slabs, and recent storm slabs will likely remain reactive Saturday.
Loose-dry avalanches may be seen from steep slopes and terrain features.
Snowpack Summary
Up to 35 cm of new snow fell over the past few days. The new snow accompanied by a strong west-northwest wind will likely redistribute some of this snow to leeward slopes and terrain features building fresh and reactive storm and wind slabs. This additional snow brings up to 60 cm of storm snow (over the past week) that sits above a plethora of old snow surfaces. In the alpine and at treeline the buried surfaces consist of stiff wind affected snow, surface facets, sastrugi, surface hoar in isolated areas sheltered by the wind, and a crust on steep solar aspects. Below 1900 m a thick crust can be found underneath the recent snow.
A solid mid-pack sits above deeply buried decomposing crust and facet layers near the bottom of the snowpack (80-150 cm deep). Though unreactive under the current conditions, steep rocky slopes and shallow snowpacks should still be carefully assessed and approached with caution.
Terrain and Travel
- Watch for changing conditions today, storm slabs may become increasingly reactive.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Avoid terrain traps where the consequence of any avalanche could be serious.
- Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Up to 35 cm of storm snow has accumulated over the past few days. Storm slabs will likely be reactive on Saturday with increased snowfall amounts adding stress to the slab. A buried weak interface may exist in some locations approximately 60 cm down and could reach its threshold, initiating a deeper slab. At this point, this interface seems spotty through the region and hasn't been as reactive as in the Lizard-Flathead region. However, something to keep this on your radar.
Loose-dry avalanches may occur from steep terrain features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Moderate to strong northwest wind will continue to redistribute the new snow building wind slabs in lee terrain features in the alpine and at exposed treeline. They may have a poor bond with old snow surfaces, for example, hard wind affected layers and pockets of surface hoar or surface facets. If the bond is poor, the wind slabs will be more reactive.
Looming cornices may be large and fragile. With respect, give them a wide berth from above and below.
Aspects: North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 6th, 2021 4:00PM
