Avalanche Forecast

Issued: Mar 27th, 2017 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Deep Persistent Slabs and Wind Slabs.

jonas hoke, Parks Canada

Waterton Lakes.

Avoid exposure to large avalanche terrain during periods of active wind loading or significant warming. Cornice falls and wind slabs may act as triggers for deep persistent avalanches.

Summary

Weather Forecast

Tuesday: Sunny in the morning, with increasing afternoon cloud.Â Moderate to strong SW wind.Â Treeline temps, High -5, Low -7Wednesday: Mostly cloudy.Â Snow flurries (up to 10cm).Â Moderate to strong SW wind.Â Treeline temps, High -2, Low -5.Thursday: Mainly cloudy, flurries possible. Light to moderate SW wind. Treeline temps, High 0, Low -2

Snowpack Summary

Below treeline a supportive surface crust has been seeing a daily melt-freeze cycle. At treeline and in the alpine, wind exposed terrain is scoured and slick. Pockets of wind slab 5-30cm deep persist in sheltered lees, these will grow with snow and wind in the forecast. The bottom of the snowpack remains faceted and weak in many locations.

Avalanche Summary

No new avalanches have been observed. Several large to very large avalanches from last week and the week before suggest that deep persistent weaknesses in the snowpack will remain as a concern well in to the spring.

Confidence

Due to the number of field observations

Problems

Deep Persistent Slabs

Facets in the bottom 1/3rd of the snowpack are persisting as a weak layer to be respected. These could easily be triggered by cornice falls, or by the weight of a person in isolated areas.

Avoid thin, rocky or unsupported slopes.Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Wind Slabs

Pockets of Wind Slab can be found in lee areas in the Alpine and at Treeline. Further wind slab development is expected on Wednesday, with wind and snow in the forecast.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Be careful with wind loaded pockets

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 30th, 2017 4:00PM