Avalanche Forecast
Issued: Mar 31st, 2021 4:00PM
The alpine rating is Storm Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeStorm slabs may continue to be reactive to skier and rider triggering, especially on wind-loaded slopes.
The spring sun packs a punch and can quickly initiate natural avalanche activity and weaken cornices
Summary
Confidence
Low - Uncertainty is due to the limited number of field observations.
Weather Forecast
Unsettled conditions will exist on Thursday as the cold front weakens and a new low develops near Haida Gwaii.
Overnight Wednesday: Snow amounts 5-10 cm with strong ridgetop wind from the southwest. Alpine temperatures near -8 and freezing levels valley bottom.
Thursday: A mix of sun and cloud with some flurries. Ridgetop wind generally light with gusty periods from the southwest. Alpine temperatures near -7 and freezing levels 900 m.
Friday: A mix of sun and cloud with snow amounts near 5 cm. Ridgetop wind strong from the South and freezing levels 900 m.
Saturday: A mix of sun and cloud. Ridgetop wind light from the southwest and freezing levels 1000 m.
Avalanche Summary
No new avalanche reports by Wednesday afternoon.Â
On Monday, reports from the Telkwa area saw a widespread avalanche cycle that occurred over the weekend. This included loose dry avalanches at all elevations up to size 2 and wind slabs up to size 2.5.Â
Avalanche size and sensitivity are expected to decrease over the next few days, however, reactive storm slabs are still anticipated, especially in wind-loaded slopes at upper elevations. If the sun comes out, it could quickly trigger natural avalanches within the new snow.Â
Cornices are large and fragile this time of year. Give them a wide berth from above and below.
Snowpack Summary
15-35 cm of snow has fallen in the region over the weekend with up to 60 cm total in the Telkwa area. This was accompanied by strong southwest to northwest wind. Fresh wind slabs may exist on most slopes due to changing wind directions. At lower elevations, much of this precipitation fell as rain below treeline. The lower elevations are now showing a firm surface crust.
Buried 70-120 cm deep, a spotty layer of surface hoar may exist on sheltered north aspects, as well as a crust on south aspects and below 1450 m. Recent observations suggest that this interface is bonding.
The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and have the potential to be triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.
Terrain and Travel
- Even brief periods of direct sun could produce natural avalanches.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Avoid freshly wind loaded terrain features.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Caution around slopes that are exposed to cornices overhead.
Problems
Storm Slabs
Reactive storm slabs may be encountered, especially in wind-loaded areas at upper elevations. A change in wind direction means that wind loading may be found on many aspects.
Keep in mind that brief periods of sun can initiate natural avalanches, especially in areas that saw high snowfall amounts.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have likely grown with the recent snow and wind. They require a large berth from above and below.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 1st, 2021 4:00PM