Avalanche Forecast

Issued: Apr 1st, 2017 4:00PM

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

tim haggarty, Parks Canada

Banff Yoho Kootenay.

A storm has brought new snow and moderate to strong winds to the area. It would be wise to let the snowpack adjust to this change as most inputs over last two months have induced avalanche cycles.

Summary

Weather Forecast

The current storm will have brought up to 10cm of new snow and rain below 1800m by the time it passes late Saturday. The moderate to strong west winds will back off into Sunday however trace amounts will continue to accumulate as temperatures cool. Clearing Monday will bring a cool morning and potentially some solar heating with very light winds.

Snowpack Summary

5 new plus 10 to 20 cm of recent snow sits over a firm 100 cm+ slabÂ resting precariously over weak basal facets at all elevations. Tests show easy to moderate sudden collapse results in these facets. New surface snow sits on a mix of soft snow in the shade, sun crust on sun exposed slopes in the alpine, and melt-freeze or wet snow below treeline,

Avalanche Summary

The new snow combined with strong winds overnight has created some small touchy windslabs in alpine areas.

Confidence

Problems

Deep Persistent Slabs

The snowpack throughout the region has a weak base and remains suspect. Approach all avalanche terrain with suspicion and exercise conservative route choices. This problem will persist for the foreseeable future.

Be aware of thin areas that may propogate to deeper instabilites.Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Wind Slabs

Fragile new cornice growth and small fresh windslabs have formed with the recent storm.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 2nd, 2017 4:00PM