Avalanche Forecast

Issued: Dec 29th, 2014 7:42AM

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

ghelgeson, Avalanche Canada

Northwest Coastal.

Watch for fresh sensitive wind slabs in exposed terrain at and above treeline.

Summary

Confidence

Fair

Weather Forecast

Synopsis: Arctic air to dominate for a few days, then warming from the north. Outflow winds should reach their peak Monday night. By Tuesday afternoon warmer Pacific air associated with the offshore upper ridge should move inland opening the door to a potential inversion or an above freezing layer between 1000 & 2500m.Tuesday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, W/NW | Ridgetop: Strong, W/NW.Wednesday: Freezing Level: Valley Bottom, potential AFL 1000 2500m; Precipitation: Nil; Wind: Treeline: Light, NW | Ridgetop: Strong, NW.Thursday: Freezing Level: 800m, potential AFL 1000 1500m; Precipitation: 3-10mm | 3-10cm; Wind: Treeline: Moderate W/SW | Ridgetop: Extreme, W

Avalanche Summary

Over the last few days we've had reports of naturally and skier-triggered size 1-2 slabs, mostly wind slabs on lee slopes at treeline and above. Explosive control with a cornice drop on Saturday produced a size 2.5 storm slab on a north-facing slope at 1400 m.

Snowpack Summary

Up to 30 cm of new snow from Friday night is being formed into new wind slabs on lee aspects as the winds shift into an outflow pattern. The mid and lower snowpack are generally well-settled. Several old crust layers exist but these appear to be well bonded.

Problems

Wind Slabs

Reverse wind loading driven by strong outflow winds is forming fresh sensitive wind slabs on lee features. Be alert for breakable, drummy or punchy snow conditions which may indicate wind slabs.

Avoid freshly wind loaded features. These may look smooth or bulbous.>Travel on ridgetops to avoid wind slabs on slopes below.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 30th, 2014 2:00PM