Avalanche Forecast

Issued: Jan 15th, 2015 8:05AM

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

bcorrigan, Avalanche Canada

Northwest Coastal.

The recent snowfall and associated winds have produced numerous large natural avalanches. Conservative terrain choices are essential at this time.

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

The recent cold front should be out of the region by Friday morning giving a small break before the next pulse of Pacific moisture arrives on Saturday through to Sunday with rain at lower elevations and snow above 800 metres. Freezing level should slowly drop to around 500 metres Thursday night or early Friday morning.

Avalanche Summary

Reports of natural avalanche activity up to size 2 yesterday around1800m on N to NW aspects . Reported to be wind-loaded pockets 20 to 30cm deep and propagating up to 40m wide.

Snowpack Summary

Strong winds have redistributed the recent storm snow into wind slabs, and rain is saturating the surface of the snowpack at treeline and below. Above treeline, a rain crust and a buried surface hoar layer 10-20cm below the surface have been reported. The mid-December crust/facet layer exists throughout the area where it hasn't been wiped out by recent avalanche activity. The November crust near the bottom of the snowpack is generally well bonded but may still be reactive in areas with shallow snowpack.

Problems

Wind Slabs

Recent storm snow is being redistributed onto lee slopes and reported to be reactive to rider triggering.

Assess start zones carefully and use safe travel techniques.>Be cautious as you transition into wind affected terrain.>Use caution in lee areas in the alpine. Recent wind loading has created wind slabs.>Be careful with wind loaded pockets while approaching and climbing ice routes.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

This buried layer is still on the radar and could be reactive with a large enough trigger.

Use caution around convexities, ridge crests, rock outcroppings and anywhere else with a thin or variable snowpack.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Jan 16th, 2015 2:00PM