Avalanche Forecast
Regions: Glacier.
A reactive storm slab at and below treeline was triggered by multiple parties yesterday in Puff Daddy, Napoleon Spur, and McGill.
Choose conservative, well-supported runs today and avoid getting pushed into a terrain trap.
Weather Forecast
Cloudy with flurries the next couple of days, then a high pressure ridge will clear things out by Thursday
Today: cloudy with sunny periods, trace snowfall, Alpine high -8*C, light/mod SW winds
Tonight: increasing cloud, 4cm, alpine high -8*C, mod S winds
Wed: flurries, 5-10cm, alpine high -7*C, gusty mod SW winds
Thurs: cloud with sun, light winds
Snowpack Summary
75cm of snowfall over the last 3 days was accompanied by strong to extreme winds from the SW. A surface hoar layer, buried Dec 26, is preserved in sheltered areas at and below treeline, down 70+cm. The Dec 13 surface hoar can still be found down 120cm and the Dec 7 crust/facet/surface hoar (aspect/elevation dependent) layer is down 135+cm.
Avalanche Summary
Overnight natural activity saw several sz 3's off Mt's Tupper and Macdonald.
Multiple MIN reports indicated people were able to trigger soft slabs, 30-70cm deep, at and below treeline to sz 2 yesterday.
Large avalanches to sz 4 were triggered by artillery control Saturday night, which ran to valley bottom and buried the highway.
Confidence
Avalanche Problems
Storm Slabs
Heavy snowfall over the weekend, accompanied by strong-extreme SW wind, has built thick storm slabs in all open terrain.
A Dec 26 surface hoar layer persists below this slab, 50-70cm deep, in sheltered areas at treeline and below.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- The new snow will require several days to settle and stabilize.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3.5
Persistent Slabs
Avalanche activity this weekend shows that large triggers (such as cornices and storm slabs) could still cause very large avalanches on these layers.
- Be wary of large slopes that did not previously avalanche.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely
Expected Size: 2 - 4
Loose Dry
Plenty of loose snow exists in sheltered locations at and below treeline. Skier triggered sluffs have the potential to collect significant mass and bury a person in a terrain trap. Sluff management is essential today.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 2