Avalanche Forecast

Issued: Feb 7th, 2016 8:07AM

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

percy woods, Parks Canada

Glacier.

The storm snow needs time to settle and stabilize. Freshly formed windslab will be touchy. Avoid overhead hazards such as cornice exposure and stick to conservative terrain.

Summary

Weather Forecast

Clear this morning with cloud moving in and isolated flurries as the day progresses. Freezing level up to 1200m today with a trend to much higher freezing levels by mid week. Ridge top winds from the SW in the light to low end of moderate today.

Snowpack Summary

Expect wind effect down into treeline with touchy windslab from moderate S-SW wind loading. Freshly formed fragile cornice will be prevalent along ridges and may react to solar trigger this morning. Upwards of 50cm of settling storm snow overlies a less dense layer and storm slab may be prone to human triggering.

Avalanche Summary

Poor visibility but expect we had a natural avalanche cycle to size 3 yesterday.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Extensive wind effect expected at and above treeline forming widespread wind slab over the low density snow of earlier last week. These slabs should be suspect and reactive to human triggering.

Watch for whumpfing, hollow sounds, and shooting cracks.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Upwards of 50cm of storm snow will be settling into a denser slab over low density snow that fell early last week. The storm slab can be expected to shear in unsupported terrain.

The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

The Jan 4th interface is a lingering concern. It can be found down 80-120cm in the snowpack. It is not evenly distributed and sporadically reactive. Storm slab failure or cornice fracture may provide the load to wake this layer up.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 8th, 2016 8:00AM