Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells.
Be aware that if triggered, avalanches may step down to deeper layers resulting in large, destructive avalanches. Keep your terrain choices conservative, as temperatures fall even a small accident can have big consequences.
Confidence
Moderate
Avalanche Summary
On Thursday and Friday explosive control produced wind slab avalanches up to size 2 on north aspects. One of which stepped down to the mid november layer.
Persistent slab activity has died down over the past week but in the neighboring central Columbia region, where it is buried deeper, this layer continues to produce rider triggered avalanches up to size 2.5
Snowpack Summary
Up to 10cm overlies variable surfaces ranging from hard old wind slabs in exposed features at upper elevations to soft, unconsolidated facets in sheltered areas.
A concerning weak layer composed of surface hoar, facets and/or a crust that formed in mid November is now buried 40 to 80cm deep. Avalanche activity on this layer has tapered off but it is likely still possible to trigger this layer in isolated terrain features at treeline.
Alpine snowpack distribution is variable, with depths ranging from 70 to 140 cm.
Weather Summary
Saturday Night
Scattered flurries bringing 5cm of new snow. Light southwest wind. Low of -18 at 1800m.
Sunday
Scattered flurries bringing up to 5cm of new snow. Light southerly wind. High of -19 at 1800m.
Monday
A mix of sun and cloud with no new snow expected. Light southwest winds and a high of -22 at 1800m.
Tuesday
A mix of sun and cloud with no new snow expected. Light westerly winds and a high of -26 at 1800m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid open slopes and convex rolls at and below treeline where weak layers may be preserved.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- In times of uncertainty conservative terrain choices are our best defense.
Avalanche Problems
Persistent Slabs
A layer of surface hoar, facets and a crust from mid november is buried around 40cm deep but can be found down as much as 80cm. This layer is most likely to be rider triggerable on slopes at treeline where the snow above feels stiff and consolidated. Avalanche activity on this layer has been decreasing over the week but it's not going anywhere so keep this in mind as you move through terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2
Wind Slabs
.
Wind slab could be found on all aspects in the alpine. These slabs could be more reactive where they overlie facets.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 1.5