Avalanche Forecast

Issued: Apr 5th, 2014 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Steady winds have decreased the ski quality. Stick to mellow lines in thin snowpack areas to avoid triggering any basal weakness. If the sun pops out Sunday, watch for increasing hazard on solar aspects.SH

Summary

Weather Forecast

Sunday expect a weak freeze and a mix of sun and cloud and minimal new snow. Winds will be Westerly and light gusting up to 75km/h in the alpine. A forecasted waming trend Monday, Tuesday with freezing levels up to 2600m. This will be accompanied by strong W winds,10-15 cm of snow in the Louise group, and maybe even some rain W of the divide.

Snowpack Summary

New wind slabs 15-25 cm thick in the immediate lees. Western areas such as Emerald and Field have a deep and stable snowpack. Contrast this with the Lake Louise, Hwy 93 N, & Sunshine areas, where there is a weaker snowpack with sudden collapse very easy compression results on the basal depth hoar. A crust exists on all but N aspects.

Avalanche Summary

A recent sz. 2 wind slab on a N aspect was observed in Yoho from the last 24 hours out of steeper terrain. No other avalanches were reported.

Confidence

Freezing levels are uncertain on Sunday

Problems

Deep Persistent Slabs

Thin areas mainly E of the divide are still susceptible to triggering basal layers causing larger avalanches. Big triggers such as cornice failures could be enough load to trigger an avalanche on the ground level

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

Isolated wind slabs in the lees of alpine ridge crests will still be susceptible to human triggering in the short term.

Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 6th, 2014 4:00PM