Avalanche Forecast

Issued: Nov 14th, 2015 8:28AM

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

Parks Canada percy woods, Parks Canada

Summary

Weather Forecast

We are in the lull between pulses of moisture.  The next pulse, starting sometime this afternoon, should bring us another 20-30cm snow by mid day tomorrow.  The avalanche danger will be increasing as the day progresses due to the incoming precipitation.

Snowpack Summary

52cm of storm snow have fallen in the last 24-36hrs accompanied by moderate to strong S through SW wind and warm temperatures. Backcountry travelers should expect freshly formed soft slabs on alpine lees. The storm slab rests on the touchy Nov 11th surface hoar layer. Expect human triggering on this layer given the right terrain.

Avalanche Summary

Field staff watched tree bombs trigger 2 size 1 slabs on the Nov 11 layer Friday. These slides were 25m wide and 50cm deep. Skiers were reporting whumphing and cracking on their tours. This morning there is a lull in precipitation until the next pulse hits this afternoon. Expect increasing avalanche danger as the day progresses.

Confidence

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

Problems

Storm Slabs

An icon showing Storm Slabs
50cm+ of storm snow is sitting on a reactive Nov 11 surface hoar layer. Warm temperatures will have assisted settling the slab and made it more cohesive. Skier triggering of these slabs is likely.
Watch for whumpfing, hollow sounds, and shooting cracks.Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Moderate to strong southerly winds have been loading alpine lee features for the last three days. Expect thick soft windslabs on immediate lee features.
Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

An icon showing Loose Dry
With the significant storm snow amounts expect sluffing in steep gully features.  This should be minor this morning but increasing with the next pulse of moisture this afternoon and evening.
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Nov 15th, 2015 8:00AM