Avalanche Forecast

Issued: Apr 14th, 2019 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

It is still very much winter up high. Storm snow and steady wind over the weekend has created wind-slabs in the alpine. Step back from skiing exposed and committing lines in the alpine until the wind-slabs have settled out.

Summary

Weather Forecast

Temperatures will remain relatively cool (-5 to -10), even in the valley (4 to -5), for the next few days. Snowfall is supposed to taper off. Convective flurries in localized areas will still be occurring however. The wind will subside to the light range (SW) today and stay there for 48 hours or so.

Snowpack Summary

20 to 50cm has fallen at higher elevations since April 9. The new snow and wind is creating windslabs on lee N and E aspects, some up to 100cm deep in immediate lees in the alpine. Facets 50 to 70cm deep produce hard shears but have not produced an avalanche for a while.

Avalanche Summary

A few small windslabs (size 1) were noted in isolated areas throughout the park today, however visibility was limited. Additionally several dry loose avalanches were observed in steep terrain in the alpine to size 1.

Confidence

Problems

Wind Slabs

Recent storm snow (20-50cm) has been redistributed by steady and moderate Westerly wind over the weekend. Some drifts in immediate lees are 100cm deep. Poor visibility has limited specific windslab observations as of Sun afternoon.

Minimize overhead exposure during periods of heavy loading from new snow, wind.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Dry

Recent storm snow has been producing loose dry avalanches from steep terrain. They are small in size and are not running particularly far.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Persistent Slabs

These slabs remain a concern on north aspects in the alpine where March winds built slabs over the facetted snow from February's cold snap. Additionally, there is uncertainty as to how this layer will react with the recent storm snow load.

Dig down to find and test weak layers before committing to a line.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Apr 15th, 2019 4:00PM