Avalanche Forecast

Issued: Feb 13th, 2014 9:09PM

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

tim haggarty, Parks Canada

Waterton Lakes.

A good time to be very conservative with your terrain choice. Human triggering should be expected on steep slopes and in open areas.

Summary

Weather Forecast

Systems are forecast to arrive Friday midday, 10 cm with some clearing Saturday morning, Saturday night,20cm, and Sunday night, 15cm, clearing Tuesday morning. Winds may diminish a bit between systems but will remain moderate and gusty W-SW. Temperatures will also remain mild with freezing levels reaching 1600m during the day.

Snowpack Summary

Up to 50 cm of snow since Monday arrived with gusty West winds and mild temperatures forming slabs above 20 cm of weak faceted crystals. Crusts exist beneath this combination on SE- Sw slopes which seem very touchy. Rapid loading is forecast to continue and threatens to wake up the weak snow that lingers at the base of the snowpack in shallow areas

Avalanche Summary

A widespread cycle to size 2 occurred Tuesday as the initial storm formed soft slabs over the facets. Remote triggering was observed at this point and should remain a concern for travelers. Natural activity diminished Wednesday, however on Thursday, a forecaster triggered a South slope above a crust: stomping a foot resulted in a sz 2.5 avalanche.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

Wind and warm temperatures have created higher density snow over the weak faceted crystals in almost any open areas. Very easy triggering means that skiers should treat all significant slopes with respect. SE to SW slopes seem extra touchy

Choose conservative lines and watch for clues of instability.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Deep Persistent Slabs

The slab of well settled snow that protects the weak snow at the base of snowpack is not very thick in many areas. As the storms continue to place stress on the snowpack, and with significant surface avalanches expected, larger events could occur.

Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Feb 16th, 2014 4:00PM