Avalanche Forecast

Issued: Feb 27th, 2014 6:47PM

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

tim haggarty, Parks Canada

Waterton Lakes.

The potential for large avalanches with the persistent slab problem still demands conservative terrain selection. Human triggering of this layer remains a possibility.

Summary

Weather Forecast

Light precipitation overnight Thurs with temperatures dropping drastically. Daytime highs in the -20s on Fri and even below -30 for Sat. Sunday will start the warming trend but is forecast to still be close to -20. Light snow forecast for Sunday again and possibly 5 to 10cm on Mon. There should be no significant solar radiation and Mod N winds.

Snowpack Summary

Thin sun crusts on SE to SSW slopes are becoming buried by light snowfall. Minimal wind effect observed at treeline, however there appears to be wind slab development in the Alpine. 80-130cm over the problematic late January facet crystals has rapidly settled into a hard slab. The potential for remote triggering and significant propagation remains.

Avalanche Summary

Natural avalanche activity has tapered off over the last couple of days. Lots of deep fracture lines still visible throughout the park from last week's big cycle. Human accidental and remote triggering of the persistent slab problem continues to be reported in nearby ranges.

Confidence

Wind speed and direction is uncertain

Problems

Persistent Slabs

Now 80 to 130 cm thick, these slabs threaten serious consequence. While the potential for triggering has dropped, do not get taken by surprise: long propagations and remote triggering may still be possible. Limit your exposure to significant slopes.

Be aware of the potential for wide propagations.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Westerly winds picked up at ridge top on Tuesday building wind slabs in the Alpine. There is a lot of snow that remains available for transport: North and East winds forecast over the next few days may create slabs in unusual locations.

Use caution in lee areas. Recent wind loading have created wind slabs.Avoid freshly wind loaded features.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 2nd, 2014 4:00PM