Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Less solar input is expected on Friday, but watch locally for its effect. Despite the arrival of spring, the snowpack remains weaker in this region. We remain wary of all steep alpine terrain on shaded aspects where crusts are absent.
Confidence
Moderate
Avalanche Summary
The local ski areas continued to get size 1 windslabs and small cornice buildup in high North terrain. No other avalanches were observed or reported Thursday.
Snowpack Summary
Surface crusts are found in most locations except north-facing alpine zones. The integrity of the snowpack is based mostly upon the strength of the surface crust when it refreezes overnight (or doesn't). In areas with no surface crust, concern remains due to the weak basal facets, which have plagued the mid and base of the snowpack all winter. This makes most steep, alpine terrain in the shallow snowpack areas of BYK suspect, and we have lower confidence in this snowpack.
Weather Summary
Strong alpine SW winds and 5-10cm of snow for Thursday night into Friday. 2000m freezing levels on Friday, mainly cloudy, with diminishing winds over the day. See below for more details
Terrain and Travel Advice
- Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
- Start your day early and be out of avalanche terrain during the heat of the day.
Avalanche Problems
Wind Slabs
Wind slabs have been reported at the ski hills over the past few days. Strong winds and light snow will add to these, although we are uncertain how prevalent they are in the forecast region.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
A 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: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2 - 3
Loose Wet
Solar input should be lower on Friday, but we may see some bouts of sun later in the day. Watch locally for its effect.
Aspects: South, South West, West.
Elevations: Treeline, Below Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5