Archived

Avalanche Forecast

Nov 10th, 2015–Nov 11th, 2015

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

Below Threshold

The avalanche danger rating below treeline will be below threshold

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

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Banff Yoho Kootenay.

Lots of keen climbers and skiers out there, but the snowpack is weak and skiing is marginal in all but high, glaciated terrain. People are triggering avalanches, and it looks like the first avalanche cycle of the winter on Friday and Saturday!

Weather Forecast

Looks like a stormy week ahead, as a NW flow brings 10 cm of snow by mid-day on Wednesday while temperatures remain cool (-8 to -11). After a short break on Thursday, looks like a pumper of a storm for Friday with amounts up to 30 cm being predicted . . . alas, accompanied by significant warming. Expect an avalanche cycle on Friday up high.

Snowpack Summary

Total snowpack depths range from 35-45 cm at treeline across the forecast area with a 5mm layer of surface hoar on the surface. Approximately 25 cm of light snow overlies slightly stronger layer that sits on the ground. Two shears exist: one on the ground, and another down 15 cm from the top. Overall this snowpack is weak with little structure.

Avalanche Summary

Slabs and loose snow avalanches have been triggered and are running naturally from alpine features, up to about size 2.5. In confined areas, the debris has run down to treeline areas. Today at Bow Summit a size 1.5 avalanche was remotely triggered on the ground, 35m ride and ran 80 m. On the Wapta, a group remotely triggered a size 2 on Mt. Olive.

Confidence

Avalanche Problems

Wind Slabs

Avalanches up to 50 cm deep are being triggered in many areas in high alpine, glaciated terrain. Watch out for windloaded features which should be avoided at this time as triggering is easy.

Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Loose Dry

The entire snowpack is unconsolidated, and loose avalanches have been observed to have run through confined gully areas - this is something ice climbers should keep in mind as they consider any overhead hazards to their routes.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2