Archived

Avalanche Forecast

Feb 26th, 2017–Mar 1st, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Waterton Lakes.

The timing of strong winds mid-week is uncertain. Watch for the hazard to increase rapidly if significant snow transport is evident.

Weather Forecast

Monday: Cloudy. Flurries morning and evening. Light Easterly winds. Treeline temps: High -10, Low -16.Tuesday: Mostly cloudy. Light Flurries. Moderate W winds beginning mid morning, trending Strong by the evening. Treeline temps: High -10, Low -13.Wednesday: Cloudy. Light Snow (up to 5cm). Strong-Extreme W winds. Treeline temps: High -9, Low -11.

Snowpack Summary

5-10cm of new snow are burying fresh Wind Slabs in N and E lees. Further Wind Slab development is expected midweek. A melt-freeze crust from mid Feb now buried up to 60cm deep, is widespread below treeline and extends into the alpine on solar aspects, the bond at this layer is currently strong but may weaken with ongoing cold temps in the forecast.

Avalanche Summary

A Cornice fall was observed on Saturday on a steep alpine N aspect. The chunks of cornice entrained enough loose snow to produce a Large avalanche. Nearby operations also reported skier triggering of small fresh Wind Slabs on Saturday.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Wind Slabs

Winds mid-week will build fresh Slabs on East facing lees. There is plenty of snow available for transport - avalanches may be Large.

Avoid cross loaded features.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 2 - 3

Loose Dry

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Be aware of party members below you that may be exposed to your sluffs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Cornices

Be cautious as you approach ridges and avoid exposure to run-out zones with cornices above.

Minimize exposure during periods of heavy loading from new snow and wind.Cornice fall could easily trigger Wind Slabs and Loose dry avalanches.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 3