Avalanche Forecast

Issued: Dec 18th, 2014 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

The West Winds have returned creating minor windslabs above treeline. Conditions below treeline remain poor due to thin coverage and even traveling on established trails is hard on skis. Little change is expected with the incoming weather.

Summary

Weather Forecast

A series of low pressure systems are approaching however models suggest they will be mostly played out by the time they get here. This should bring a few temperature variations however it looks like temperatures will remain below freezing at Little Prairie for the period. Precip amounts will be minimal with mainly cloudy skies and west winds.

Snowpack Summary

Surface hoar formed in open areas on the 10 to 20 cm of snow that fell Dec 13 on a solid rain crust. SW winds began redistributing this on Tuesday likely forming wind slabs treeline and above. Beneath the crust the snowpack is now beginning to refreeze giving it considerable strength treeline and below however basal facets may exist above 2300m

Avalanche Summary

No new avalanches have been seen or reported

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

The SW winds have blown for two days to affect ridgelines at treeline and above. Expect to find small, thin, freshly formed windslabs lurking near ridgelines and in the lee of open features. We would expect these to be more developed in the alpine.

Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The snowpack gained strength this week as it cooled down. The facets and associated crust found near the base of the snowpack likely only remain a problem at elevations above at least 2400m.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Dec 21st, 2014 4:00PM