Avalanche Forecast
Regions: Glacier.
The new surface storm slabs are reactive and have been observed to propagate widely from human and explosive triggers.
Stick to supported terrain with limited exposure to overhead hazard, where remote-triggering could bring the snow slope down onto you.
Confidence
Moderate
Avalanche Summary
Avalanche control Mon morning had good results, with numerous avalanches from sz 2-3.5 resulting from both natural and explosive triggers. The surface storm slab was propagating widely on the crust and/or the surface hoar/facet combo from March 31.
On Sunday, an experienced group remote-triggered an avalanche on a NE facing slope by the Cleaver, injuring 1 person.
Snowpack Summary
15cm Monday morning added to the 45-60cm that has buried the Mar 31 layer (crust on solar aspects, facet/surface hoar on polar aspects).
The snowpack is generally strong. However, the Nov 17 basal weakness can still be found near the ground in many locations. It may be possible for this layer to become active during this warm storm cycle.
Weather Summary
Flurries and dropping temps are forecasted for the next 2 days.
Tonight: Flurries, 10cm, Alp low -4*C, light gusty SW winds, 1400m FZL
Tues: Flurries, 5-10cm, Alp high -4*C, light gusting moderate SW winds, 1500m FZL
Wed: Flurries, 5cm, Alp high -5*C, light SW winds, 1600m FZL
Terrain and Travel Advice
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Avalanche Problems
Storm Slabs
New snow and strong SW winds Sunday night built touchy storm slabs. These slabs are failing on crusts on solar aspects and surface hoar/facets on N'ly slopes. The slabs were observed to propagate 50-75m from explosive triggers on all aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1.5 - 3
Loose Wet
Freezing levels are dropping, but the overnight crust recovery has been poor, only reaching -2*C at treeline and remaining at 0*C at valley bottom. Wet loose avalanches remain a concern until we see a significant drop in temps.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 2.5
Deep Persistent Slabs
We are bringing the Deep Persistent problem back due to the rise in freezing levels and rain at lower elevations. There has been no activity on this layer for several weeks, but it's uncertain what will be enough to re-activate this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely
Expected Size: 2 - 4