Avalanche Forecast

Issued: Dec 17th, 2012 9:57AM

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

Avalanche Canada jfloyer, Avalanche Canada

Summary

Confidence

Fair - Due to limited field observations

Weather Forecast

Tuesday: Mostly a bright, dry day with some sunshine. Ridgetop winds around 30 km/h from the west. Treeline temperatures around -10C.Wednesday: A Pacific frontal system affecting the coast will bring only light amounts of new snow to this region (less than 5cm expected). Winds will rise to around 60 km/h from the SW. Treeline temperatures will rise to around -4C.Thursday: Light snowfall (around 5 cm) is expected, with light southerly winds and treeline temperatures around -8C.

Avalanche Summary

Small loose snow avalanches have been from steep terrain in the recent low density storm snow. Due to our limited observations for this region at this time, your avalanche observations are welcome at forecaster@avalanche.ca

Snowpack Summary

The upper snowpack comprises deep amounts of unconsolidated snow in sheltered locations, and soft slabs in open, exposed locations. These slabs are most likely immediately behind ridge crests and downslope ribs. There's ample recent snow available to fuel slab development if winds pick up. Overall, the top and mid-snowpack is reported to be settling well. Persistent and Deep persistent instabilities (surface hoar and an early November crust, respectively) located in the middle and near the bottom of the snowpack may still be a concern but there's little recent evidence of them. It is important to know that we have very limited observations for this region. Digging down and making your own observations, especially in thinner snowpack areas, remains a good idea to assist safe slope selection. You're looking for weak layers that pop or drop in stability tests. Any observations from the field are welcome at forecaster@avalanche.ca.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are able to set up readily at this time due to the amount of low density new snow available for wind transport. Buried wind slabs are reported to exist below some of the new snow in exposed locations, especially on N and E aspects.
Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>Whumpfing, shooting cracks and recent avalanches are all strong indicators of an unstable snowpack.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Dec 18th, 2012 2:00PM

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