Archived

Avalanche Forecast

Feb 11th, 2013–Feb 12th, 2013

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Sea To Sky.

Confidence

Good

Weather Forecast

Synopsis: A frontal system is moving across the area bringing generally light snowfall Monday night and into Tuesday. On Wednesday and Thursday, a ridge of high pressure dominates the region.Tuesday: Around 5 cm new snow, with SW winds gusting to 40km/h at ridgetop. Freezing level around 800m.Wednesday: Lingering flurries in the morning, then clearing. Freezing level around 600m. Moderate NW winds in the morning, diminishing through the day.Thursday: Dry and sunny. Freezing level 800m in the afternoon. Light NW winds.

Avalanche Summary

There were reports of loose snow avalanches on solar aspects to size 1.5 and cornice releases on northerly aspects up to size 3 over the weekend during warm weather.

Snowpack Summary

Fresh wind slabs are likely forming in alpine areas in response to new snow and wind. Buried surfaces of concern from the previous storm (the Feb. 3 interface) comprise mostly sun crusts. The new snow is bonding reasonably well at this interface in most locations with the highest concern being the bond to crusts on south and west facing terrain. The January 23rd interface (crusts, facets and surface hoar crystals) lingers in isolated locations. This layer seems to be rounding and bonding under current conditions. The most recent report of activity on this layer was a size 2.0 avalanche from Feb 6th. The mid pack is generally well settled. Total snow depths vary from around 400 cm in the south to around 180 cm in the north.

Avalanche Problems

Wind Slabs

New and old wind slabs exist in the region behind ridges and ribs in exposed areas. Where new snow overlies a crust there is an increased likelihood of triggering.

Watch freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4