Avalanche Forecast

Issued: Feb 5th, 2015 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

Hazard is on the rise however weather forecasts remain uncertain with respect to freezing levels and precip quantities. Watch the weather closely as you plan your trip!

Summary

Weather Forecast

Models are just starting to agree with moderate to heavy precip through Saturday morning and light precip continuing through Sunday. Freezing levels however hold some uncertainty: they could reach 2500m but have held at 2000m right now. Fingers crossed! Moderate SW winds should continue for the period with strong winds possible Friday.

Snowpack Summary

Rain below 1900m. Steady snowfall Thursday built a 10-15cm storm slab above the Jan 31 crusts (that extend everywhere except shaded aspects above 2300m) while gusty SW winds blow this new snow into slabs 40cm thick in lee TL and ALP features. Above 2000m on the shaded aspects concern for the Dec facets and crust layer down 40 to 80cm remain.

Avalanche Summary

Small slabs of snow failing between skier's tracks were the only indication seen while skiing today that there may be trouble ahead with the bond of the new snow to the crust.

Confidence

Freezing levels are uncertain on Friday

Problems

Storm Slabs

These slabs could grow rapidly with mild temps, moderate winds and heavy snow forecast. If freezing levels rise wet slabs could be very touchy at lower elevations. Monitor slab depths and resistance by feeling for the crust. Watch forecasts closely.

The new snow will require several days to settle and stabilize.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

Now 40 to 120cm deep these slabs continue to stand out as a real concern in the TL and ALP areas that do not have strong surface crusts. Be particularly mindful in thin snowpack areas where this layer is more likely to be triggered.

Dig down to find and test weak layers before committing to a line.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Feb 8th, 2015 4:00PM