Avalanche Forecast

Issued: Mar 13th, 2014 4:22PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

Conditions are still tricky out there. The snowpack needs to adjust to its new load. Danger ratings may be lower in deeper snowpack areas where the recent snow fell on a stronger snowpack

Summary

Weather Forecast

Expect light precip on Friday with moderate to strong W alpine winds. Saturday will be a short break before the bulk of the storm arrives. Forecasts are showing 30-40 cm Sat PM and into Sunday. Freezing levels will rise to ~1700m during the day and drop to valley bottom at night throughout the period.

Snowpack Summary

Strong west winds have created widespread wind effect in the ALP and at TL. 10-15 cm of new snow (north) and 2-5 (south) lies on top of a 3-5 cm thick sun crust on solar aspects and dry snow on polar aspects. Below 1500m a rain crust exists. The Feb. 10th layer is down 50-110 and is reactive with large whumphs and sudden collapse results today

Avalanche Summary

A sizable cornice released on the south face of Mt. Bourgeau today which didn't pull a slab on the slope below. Solar aspects have been warming up and we've seen loose wet avalanches out of steep rocky terrain, but the winds have kept things generally cool. Conditions remain touchy and we are still only just coming out of a major avalanche cycle

Confidence

Forecast snowfall amounts are uncertain on Sunday

Problems

Persistent Slabs

In thinner snowpack areas, this layer is still touchy as shown by numerous large whumphs and sudden collapse results today. It is especially reactive on solar aspects where there is a buried sun crust and may be less reactive in deeper snowpacks

Avoid areas with overhead hazard.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Recent moderate to strong west winds have stripped fetches and loaded the lees. Lee slopes will be quite touchy and the loading may be enough to trigger natural avalanches

Use caution in lee areas. Recent wind loading have created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 14th, 2014 4:00PM