Avalanche Forecast
Regions: Glacier.
Choose conservative, low consequence terrain and give the storm snow more time to settle.
Rogers pass has received up to 80 cm of new snow since Saturday and the storm slab remains reactive to human triggering.
Confidence
Moderate
Avalanche Summary
Natural activity is starting to tapper off but human triggering remains likely.
A large natural avalanche cycle (up to size 3.5) began overnight Saturday with numerous avalanches reaching the ends of their runouts.
Artillery control Sunday night produced avalanches up to size 4.
A group up the Asulkan Valley triggered a size 2 avalanche Sunday, which partially buried one of their party members.
Snowpack Summary
Up to 80cm of new snow since Saturday with periods of strong to extreme SW winds has formed a widespread storm slab at all elevation bands. This slab is bonding poorly to our previous drought layer of old breakable crust & widespread surface hoar. This interface is reactive in snowpack testing & could easily be human triggered.
Two persistent weak layers (PWL) from Jan/Feb are now buried well over a meter. Large triggers such as storm slab avalanches may step-down to this layer
Weather Summary
Unsettled weather ahead this week, with a weak front moving through Thurs.
Tonight Isolated flurries, trace precipitation. Ridge wind S 20 km/h. Freezing level (FZL) 800m.
Wed Flurries, ~5cm.Alp high -4°C. Ridge wind S 25-35. FZL 1700m.
Thurs Flurries, 6cm. Alp high -3. Ridge wind SW 15-30. FZL 1500m.
Fri Cloudy with sunny periods & isolated flurries. Alpine high -7. Ridge wind SW 10-20.
Terrain and Travel Advice
- Be aware of the potential for larger than expected storm slabs due to buried surface hoar.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Avalanche Problems
Storm Slabs
80cm of snow, along with strong SW winds, has created a widespread storm slab that is reactive on all aspects and elevations.
Human-triggered avalanches are likely, given that this new slab sits atop a widespread surface hoar/suncrust layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 3
Persistent Slabs
There are buried persistent weak layer (PWL) 's down 140-170cm in the snowpack, consisting of suncrust/facets/surface hoar. There is potential for step-down avalanches with the overlying storm slab triggering these deep layers, resulting in large, destructive avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2.5 - 4