Avalanche Forecast

Issued: Apr 28th, 2015 8:00AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Loose Wet, Persistent Slabs and Cornices.

ali haeri, Parks Canada

Glacier.

A good plan is to avoid the backcountry until things cool down. Temperatures have already soared well into the positive values at 2100m this morning. The deterioration of the snowpack will be very rapid today combined with the weak overnight freeze.

Summary

Weather Forecast

Warm air ahead of a cold front will give us our highest freezing levels today reaching ~3200m. A Pacific system will be making its way inland by late tonight into Wednesday giving moderate amounts of precipitation, freezing levels will lower to around 1750m. Alpine winds will pick up to 30-50km/hr from the southwest.

Snowpack Summary

Another weak overnight freeze. The crust has been thinner between 1600-2000m and will break down faster there than at lower elevations. The April 10 layer is down 30-60cm. Moist snow will almost certainly be found on most aspects and elevations. Any dry snow that could be found in high alpine north aspects will be come moist by later today.

Avalanche Summary

2 loose wet avalanches observed in the highway corridor yesterday.

Confidence

Problems

Loose Wet

It wont take long for the crust to break down today. This crust is not as strong between 1600m-2000m and will break down in that elevation band first.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Minimize exposure when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Persistent Slabs

Daytime warming, loose avalanches and skiers can trigger this layer.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Cornices

Cornice hazard will increase with these rising freezing levels

Cornices become weak with daytime heating, so travel early on exposed slopes.Give cornices a wide berth when travelling on or below ridges.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Apr 29th, 2015 8:00AM