Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Cooler temperatures are forecast for Wednesday, but pay attention to solar radiation and how quickly the day is warming up. Some loose wet avalanches may occur if day is warmer then forecasted. Plan on starting and finishing your day early.
Confidence
Moderate
Avalanche Summary
Some small wet loose avalanches out of steep solar terrain were reported on Tuesday afternoon.
On Saturday, skiers in the Ferris Glacier area remote-triggered a wind slab 60 cm deep on NE alpine terrain at ~2750 m.
On Friday, skiers remotely triggered a wind slab at ~2850 m on St. Nicholas size 2.5 that stepped down to deeper layers in a rocky area, and occurred on steep, unsupported ENE facing terrain.
Snowpack Summary
Crusts on solar aspects to ridgetop, with crusts on all aspects at treeline and below. 20-40 cm of dry snow on north-facing alpine slopes with wind slabs in alpine lee areas.
In thinner snowpack areas a 30-70 cm stiff midpack sits over weak facets and depth hoar. On high north slopes, this weakness remains a concern. Elsewhere, crusts in the upper snowpack overlay this midpack slab. If these crusts are thick, and remain frozen, they provide some strength over the weakness.
Weather Summary
Wednesday will bring a mix of sun and cloud and slightly cooler temperatures with freezing levels around 18-1900m. Winds forecast to be light to moderate from the northwest. Friday will bring clear skies and higher freezing levels.
Terrain and Travel Advice
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- Wind slabs are isolated, but may remain reactive.
Avalanche Problems
Wind Slabs
Residual wind slabs may persist in lee high alpine features. Watch for these wind slabs as you transition into the higher alpine terrain.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
A midpack slab up to 80 cm thick sits on the weak, facetted lower snowpack. On all but high north aspects, recent sun crusts and the March 27 rain crust cap this slab, providing some security. Use caution in higher, thin snowpack areas or where these crusts are weak or breaking down with heating.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3