Avalanche Forecast

Issued: Mar 14th, 2014 8:03AM

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

danyelle magnan, Parks Canada

Glacier.

Deep reactive layers and another series of storms approaching deserve your attention. The snowpack this year is challenging, and has been surprising recreationalists and professionals alike. Be very cautious if you head into the backcountry.

Summary

Weather Forecast

A quick moving front will pass through the area today, bringing ~10cm with strong SW winds. A strong storm will arrive on Sat afternoon. Up to 20cm of snow is expected Sat, with moderate SW winds transporting snow and rapidly loading slopes. Another 16cm is expected Sunday. Freezing levels should stay below 1400m.

Snowpack Summary

Last weeks storm snow has settled over the March 2 crust down ~1m. Instabilities within the slab, and the crust, are becoming unreactive. The Feb 10 interface is down 1.5-2m and continues to react in snowpack tests. It has been most reactive recently on solar slopes, see below. Below this, the mid to lower snowpack is well settled.

Avalanche Summary

Yesterday, a group of ski tourers remotely triggered a size 2.5 avalanche from the thin rocky ridge at 2650. The avalanche failed over 30m away on a S aspect. It was ~1m deep, likely failing on the Feb 10 PWL, and ran over 400m. With the recent sunshine, numerous natural solar triggered avalanches to size 3 have been occurring daily.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Persistent Slabs

We are expecting over 50cm of snow this weekend, with strong westerly winds. This will rapidly load the persistent weak layer down 1.5-2m. This layer continues to be reactive and surprise people throughout the region, producing impressive avalanches.

Be aware of thin areas that may propogate to deeper instabilites.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Storm Slabs

Lots of new snow, with wind, through the weekend will form a new storm slab. This slab will likely be most reactive where it overlies suncrust, but will also bury small surface hoar. If triggered, this slab may also step down deeper.

Choose conservative lines and watch for clues of instability.Minimize exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 15th, 2014 8:00AM