Archived

Avalanche Forecast

Feb 3rd, 2013–Feb 4th, 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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Purcells.

Confidence

Fair - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

Overnight and Monday: Strong Northwest winds with 2-3 cms of snow and alpine temperatures down to -8.0. A few cms during the day with gusty Northwest winds and freezing levels rising to about 1000 metres.Tuesday: A warm pulse of moisture is expected to bring 5-10 cms to elevations above 1200 metres with strong Southwest winds.Wednesday: Light Southwest winds and another 3-5 cms with freezing levels rising back up to about 1100 metres.

Avalanche Summary

Some pockets of wind slab up to size 1.5 were reported, and sluffing up to size 1.0 continues to be reported from steep terrain.

Snowpack Summary

Wind slabs continue to develop in the alpine and at treeline. Forecast strong Northwest winds are expected to further develop these wind slabs. The recent storm slab continues to be reactive down 30-50 cms at treeline and below. Below freezing temperatures overnight have helped to strengthen the moist surface layers that developed during the weekend warm period. Rising freezing levels forecast during the next pulse of moisture may weaken the old storm slab at lower elevations. The mid-pack is well settled and there are no reported deep layers of concern.

Avalanche Problems

Wind Slabs

Old wind slabs continue to be reactive to light additional loads. Expect new wind slabs to develop with the next pulse of moisture.

Be cautious as you transition into wind affected terrain.>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

Persistent Slabs

The recent storm snow continues to settle into a cohesive slab above weak layers and variable old surfaces. This slab may become more reactive during the forecast warm temperatures below treeline.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4