Avalanche Forecast

Issued: Apr 3rd, 2017 7:48AM

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

chris gooliaff, Parks Canada

Glacier.

Danger levels will increase with direct sunlight and with warming throughout the day. Pay attention to the large cornices overhead, and don't forget that low elevation crusts may have broken down by mid-day.

Summary

Weather Forecast

Sunny with cloudy periods today with an alpine high of -7*C. Freezing levels will rise to 1300m, but it will certainly feel warmer in the direct sun. Winds will remain light from the west. Tuesday will see similar conditions but slightly higher temps.

Snowpack Summary

Storm snow in the alpine totaled 20-30cm over the weekend. Moderate to strong SW winds have redistributed it and formed wind slabs in alpine lee features. Cold overnight temp's have formed a supportive crust below tree-line. Cornices are big in the alpine and if they fail, they may trigger one of the multiple crusts lingering in the upper snowpack.

Avalanche Summary

One notable cornice-triggered size 3 avalanche from Railroad Gunners made it down to the fan. Several skier accidental and skier cut size 1.5's were reported from Bonney Moraines, N Cheops, and Balu Ridge descending into 8812 bowl. These were reported to be 20-30cm deep, running on the storm interface on N aspects and on a crust on SE aspects.

Confidence

Due to the number of field observations

Problems

Wind Slabs

The weekend's storm snow has been redistributed into widespread wind slabs in the alpine and open tree-line features. These slabs were reactive to light loads yesterday and will need time to bond to the underlying interface.

Use caution in lee areas. Recent wind loading has created wind slabs.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

The large cornices hanging on the ridge-lines are fragile and they pack a monster punch if they fail on the slopes below. These massive triggers have the potential to trigger deeper layers and cause very large avalanches.

Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 4th, 2017 8:00AM