Avalanche Forecast

Issued: Jan 26th, 2012 9:32AM

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

jlammers, Avalanche Canada

Sea To Sky.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain on Sunday

Weather Forecast

Friday: mix of sun and cloud and very light flurries / moderate northwest winds / freezing level at 600m Saturday: increasing cloud in the afternoon with snowfall developing later in the day / winds increasing to strong and southwest by the end of the day / freezing level at 700m Sunday: moderate to heavy snowfall / moderate southwest winds / freezing level climbing to 1100m

Avalanche Summary

Explosives control on Thursday produced mostly surface results to size 1.5. The exception was a size 3 slab that was 2.5 metres deep on a north facing alpine slope.

Snowpack Summary

Mother nature pummeled the Sea to Sky region over the last few days. Over 115cms of snow that fell since last weekend has now settled to about 80cm. Recent southwest winds have consistently hovered in the strong to extreme category and wind drifts have been reported up to 3 metres high. The recent storm snow is resting on a variety of older snow surfaces. These surfaces include previous cold, dry low density snow which may have had seen some faceting, old wind slabs, and crusts. These interfaces have most likely gained considerable strength, but it is reasonable to believe that any avalanche activity could step down to any of these interfaces.Previous concerns about deeper persistent weak layers appear to have diminished.Snowpack depths at treeline are in the region of 260 cm.

Problems

Wind Slabs

Heavy snowfall amounts and strong winds have set up deep new wind slabs. They may be found in unsuspecting places lower on the slope.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Storm Slabs

Heavy amounts of storm snow have fallen on a variety of old surfaces. A deeper release is decreasing in probability, but would have a high consequence

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 5

Cornices

Strong winds and new snow have added mass to sensitive cornices. They may be destructive by themselves, and may also be a trigger for the slope below.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 6

Valid until: Jan 27th, 2012 8:00AM