Avalanche Forecast

Issued: Mar 28th, 2014 4:59PM

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

Lisa Paulson, Parks Canada

Banff Yoho Kootenay.

Light wind with strong gusts are forecast and this may create a more widespread wind slab issue. This combined with the other field results today led us to bump up the hazard. Pick your lines carefully and some incredible skiing/boarding can be had!

Summary

Weather Forecast

Cloudy skies, light winds and moderate to strong gusts forecasted for tonight and tomorrow. Flurries for Sunday, 5-10 cm expected, greater amounts in the Bow Summit area.

Snowpack Summary

Up to 47 cm (sunshine & yoho) over past 3 days, generally bonding well and has had little wind effect so far. In shallow or weaker snowpack areas, the basal facets and Feb 10 layers are still reactive. In deeper uniform North aspects, these problems are less of a concern. South aspects, there are a few buried suncrusts that may pose a problem.

Avalanche Summary

A few soft storm slab naturals to size 2 in immediate lees in the alpine, sluffs up to size 2, and 2 days ago - a size 2.5 to ground in a shallow snowpack area in Little Yoho, East facing alpine slope. A couple of whumphs today in Purple Bowl and above Elevator shaft (Louise region) on the basal facets that propagated 50-300 m.

Confidence

Problems

Loose Dry

More sluffs observed today on South and North aspects, up to size 2. Watch your exposure to steep terrain overhead, especially if the wind gusts pick up.

Be cautious of sluffing in steep terrain.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

In areas with uneven, shallower or weaker snowpacks, we remain concerned with the Feb 10th midpack layer of crust/facets/surface hoar (Kootenay burns) and the basal facet layer. Stick to lower angled well supported terrain in these areas.

Be wary of slopes that did not previously avalancheUse conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

This is not yet a wide spread issue and only a few soft wind slabs to size 2 were observed today in the immediate lees of terrain. Monitor slab development with wind gusts tomorrow as this may develop into more of a problem.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 29th, 2014 4:00PM