Avalanche Forecast
Issued: Nov 28th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
jleblanc,
Avalanche Canada
Storm slabs instabilities will remain reactive at upper elevations. Given how uncertain conditions are, avoid big terrain at this time.
Summary
Confidence
Weather Forecast
Precipitations will ease further Sunday night as rain changes into snow as freezing levels settle down closer to 300 m. A brief break is expected Monday morning before snowfalls intensify rapidly with the approach of the next intense storm Tuesday and Wednesday.
SUNDAY NIGHT: Cloudy / Strong, southwesterly winds / Low of -6 / Freezing level lowering to 300 m.
MONDAY: Cloudy / Moderate southwesterly winds / High of -4 / Snow 15-20 cm late afternoon with extreme winds / Freezing level rising to 1000 m by the end of the day.
TUESDAY: Snow/rain; 40-60 cm / Extreme, southwesterly winds / High of +4 / Freezing level rising to 1500 m.
WEDNESDAY: Snow/rain; 10-20 cm / Extreme, southwesterly winds / High of 0 / Freezing level rising to 1000 m.
Avalanche Summary
No new avalanches were observed Sunday due to poor visibility, but likely some natural avalanche occurred at upper elevations with the last heavy snow / rain episode.
If you go out in the mountains, please post your observations and/or photos to the Mountain Information Network!
Snowpack Summary
Southern portion of region (around Terrace):
15-25 of moist snow fell overnight Saturday into Sunday as the rain line was around 1500 m. This adds to the 20 cm of recent snow which sits on top of a hard crust. Extreme southwesterly winds have also made these fresh storm slabs most reactive on lee features at treeline and above.
A prominent crust can be found near the bottom of the snowpack.
Treeline snowpack depths are estimated to be around 200-300 cm.
Northern region (around Bear Pass):
20 cm of moist snow fell overnight Saturday into Sunday as the rain line was around 1200 m. This adds to the 60-80 cm of recent snow which was heavily wind affected. Extreme southwesterly winds have made these fresh storm slabs most reactive on lee features at treeline and above.
Below the recent snow, two weak layers of surface hoar have been reported in sheltered areas, as well as a crust near the bottom of the snowpack.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Be especially cautious as you transition into wind affected terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Storm Slabs
New snowfalls (15-25 cm) and wind have formed large reactive storm slabs at treeline and above. These slabs are especially deep on leeward features on north aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 29th, 2021 4:00PM
