Avalanche Forecast
Regions: Banff Yoho Kootenay.
Avoid avalanche terrain on Monday. New snow and wind continue to load slopes. Wait for the storm to pass and for the snow to settle before venturing back out into avalanche terrain.
Weather Forecast
Models suggest that another 20-30cm is expected overnight on Sunday, into Monday morning. In step with the continued delivery of snow load is strong wind from the West that will continue throughout Monday. Valley temps will rise above zero Monday afternoon with the alpine temps climbing to roughly -5.Â
Snowpack Summary
Up to 30cm of storm snow since Fri evening. Rain below 1800m Sat afternoon. Down 30-50cm a thin melt-freeze crust exists in some areas that may be present up to 2500 m on solar aspects. Below this is another 10-20 cm of facetted snow over a melt-freeze crust at or near the ground. The snowpack is 45-65cm deep at treeline with more in the alpine.
Avalanche Summary
Lake Louise ski area reported a widespread natural cycle up to size 2. At Bow Summit, forecasters observed 3 loose dry avalanches (size 1.5) that ran out of steep rocky terrain to the fans below. Forecasters are expecting that Saturday afternoon is the start of a major avalanche cycle.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Monday
Avalanche Problems
Wind Slabs
New snow load, wind and warm temps are rapidly forming wind slabs, predominantly in the alpine. The storm is expected to continue well into Monday only perpetuating this problem. Human triggering is likely.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Very Likely
Expected Size: 1 - 2
Storm Slabs
Where wind is less of a factor, storm slabs will be present due recent snowfall. While the storm slab problem will not likely linger for days on end, it will certainly be a problem as the storm continues throughout Monday. Expect slabs 20-40cm thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Very Likely
Expected Size: 1 - 2
Loose Dry
Due to recent snowfall (30cm and counting) expect loose snow avalanches to be a certainty, especially in steep confined spaces. Ice climbers should avoid avalanche terrain and especially steep gullies, even below treeline.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
Aspects: North, North East, East, South East.
Elevations: All elevations.
Likelihood: Very Likely - Certain
Expected Size: 1 - 2