Avalanche Forecast
Regions: Banff Yoho Kootenay.
There have been many different weather inputs over the last few days and a couple of very close calls with skier triggered avalanches.
Weather Forecast
A bit of an inversion is setting up for Friday. Temperatures will stay below freezing (-5C to -2C) in the alpine with a mix of sun and cloud, and light to moderate NW winds. Friday night winds will turn west and blow over 100kmh, weakening over the day. The alpine will cool Saturday with temperatures in the -10 to -15C range, and -5C at 2000m.
Snowpack Summary
10-15 settled hst with wind over the past few days has added to windslabs at treeline and above. These overlie facets in many places, producing moderate test results. The Dec. 2 crust and facets are generally 60-90cm deep in the snowpack. Some thin snowpack areas have lingering basal depth hoar and facets.
Avalanche Summary
On Wednesday, a skier remote size 3 was triggered in Kootenay, running full path. It stepped down to the Dec 2 crust and facets. A skier also got caught in an avalanche in the Lake Louise backcountry late Thursday, which appears to have been initiated at treeline. Ski hills were also reporting explosive triggered avalanches to size 2.5.
Confidence
Due to the number and quality of field observations
Avalanche Problems
Wind Slabs
Windslabs are prevalent in alpine and some treeline terrain which may overly facets. In some circumstances these have been enough to initiate deeper layers in the snowpack.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
The Dec 2 crust and facets down 60-90cm have become more active in the region. If initiated, they can produce large avalanches. It has been most active below 2000m in Kootenay, but has also been reported in other shallow areas East of the divide.
- Forecasters are operating with alot of uncertainty at this time.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3