Avalanche Forecast

Issued: Mar 26th, 2017 4:02PM

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

Avalanche Canada mgrist, Avalanche Canada

Wind and snow has built fresh wind slabs. Avoid lingering in the runout of avalanche paths as cornice fall could trigger a large avalanche.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're looking at a series of small systems moving through the region during the forecast period. The winter weather train keeps rolling into town! MONDAY: Flurries Sunday overnight into Monday (5-10cm possible). Moderate southwest wind, freezing level around 1800 m with alpine temperature around -2 C.TUESDAY: Cloudy with isolated flurries. Moderate southwest wind, freezing levels 1700m.WEDNESDAY: Snow (5-10cm possible) moderate south wind, freezing levels 1900m, alpine temperature around -1 C.

Avalanche Summary

On Sunday, explosives control work yielded a pair of Size 2 storm slabs (25-50cm thick) running on southeast aspects near 2000m elevation near Fernie. The Moccasin glide crack slid sometime Saturday night, running to ground. See here for photo and more info.On Saturday, many explosive-triggered storm slabs to Size 2.5 were reported near Fernie, on primarily northeast aspects from 1700-2100m, having average depths of 20-40cm, running on the March 21st rain crust.Expect wind slabs to develop as winds continue to transport snow at treeline and in the alpine.

Snowpack Summary

The storm on Friday-Saturday had some intense convective activity which brought locally heavy snowfall (or graupel) and storm totals of 15-35cm. Winds became moderate westerly at ridge top with lots of transport.Snow at the middle of last week delivered 15-25 cm of heavy snow at higher elevations, while rain soaked the snow below about 1800 m. All the recent snow (now a layer roughly 40cm thick) is bonding variably to the hard (March 21st) rain crust (10cm thick) that capped the snowpack at all elevations: In some areas the recent snow is showing signs of significant propagation and peeling off the crust with the additional loading of the latest storm snow (see Avalanche Summary above).Isolated basal facets exist in shallow snowpack areas and still have the potential to produce destructive full-depth avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs
Moderate winds have formed wind slabs in the lee of exposed terrain.
If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be alert to conditions that change with elevation and aspect.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 27th, 2017 2:00PM

Login