Avalanche Forecast
Regions: Waterton Lakes.
Rising freezing levels will stress our pre existing wind slab problem and create potential for wet loose avalanches later in the week.
Keep in mind that a persistent slab lurks deep in the snowpack and give cornices a wide berth as things warm up.
Weather Forecast
Tuesday: Cloudy with sunny periods and isolated showers. 5cm of snow at Cameron Lake with Rain in the townsite. Moderate SW wind with 70km/h gusts.
Wednesday:Â Sunny with cloudy periods. Freezing level rising to 2100m. Moderate SW wind with strong gusts.
Thursday: Mostly Sunny. Freezing level 2200m. Light to Moderate SW wind with 60km/h gusts.
Snowpack Summary
Strong SW wind has caused significant cornice growth and added to surface wind slab. 20-50cm wind slab sits on top of the weak February 14 facet layer which is above a melt freeze crust at treeline and below. The remainder of the midpack is made up of dense facets and decomposing crusts, with early season ice crusts forming the base.
Avalanche Summary
A natural size 1.5 wind slab avalanche was noted on a SE aspect at 1900m on the Akamina Parkway. We estimate this avalanche occurred over the weekend when visibility was poor.
Confidence
Freezing levels are uncertain on Thursday
Avalanche Problems
Wind Slabs
Recent strong to extreme southwest winds have formed thick wind slabs in the alpine and treeline.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Loose Wet
Rising freezing levels will make Wet Loose avalanches a major concern on Wednesday afternoon and Thursday. Be mindful of your overhead hazard be aware that warm temperatures may cause cornices to fail.
- If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.
Aspects: North East, East, South East, South, South West, West, North West.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 3
Persistent Slabs
This problem is most prevalent at and below treeline. The probability of triggering this layer is decreasing by the day but the consequence is still very high due to the depth of burial down 20-50cm and the potential for wide propagation.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- Be aware of the potential for wide propagations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 3