Avalanche Forecast
Regions: Glacier.
The storm slab continues to build on Thursday with new snow and strong winds in the forecast.
Human triggered avalanches remain likely. Choose conservative, low consequence terrain and give the storm snow more time to settle.
Confidence
Moderate
Avalanche Summary
Natural activity is starting to taper off but human triggering remains likely.
Large avalanche debris and fracture lines from last weekend are still easy to see. The natural avalanche cycle had avalanches up to size 4, running full path.
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
Another frontal system will bring more snow to the region on Thursday.
Tonight Scattered flurries, Snow: 5 cms. Ridge wind S 20-35 km/h. Freezing level (FZL) 1200m.
Thurs Periods of snow, 15cm. Alp high -2. Ridge wind SW 20 gusting 50 km/hr. FZL 1700m.
Fri Cloudy with sunny periods & isolated flurries. Alpine high -10. Ridge wind SW 20km/hr. FZL 900m.
Sat Flurries, ~5cm. Alp high -7°C. Ridge wind S 10-25. FZL 1700m.
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
Recent new 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
Expected Size: 1 - 3
Persistent Slabs
There are buried persistent weak layer (PWL) 's down 100-150cm 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. This would result in large, destructive avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2.5 - 4