Archived

Avalanche Forecast

Feb 27th, 2013–Feb 28th, 2013

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

The February 12th surface hoar is the main concern, and is most reactive in areas at and below treeline where it sits on a sun crust, or has been undisturbed by skier traffic. Be cautious venturing into new or previously unridden terrain.

Weather Forecast

Mostly dry until Friday, when warm temps and moderate precipitation should carry the scent of pineapples from Hawaii. Winds are forecast to be light today with some gusty conditions up to 50kph and light Thursday morning, then rise to high on Thursday afternoon heralding the storm on Friday.

Snowpack Summary

Top 30 cm of settling storm snow with a soft breakable crust on top where it is exposed to the sun. Feb 12 surface hoar and crust layers down 40-55 cm. Mid pack is well settled.

Avalanche Summary

Recent avalanche control west of Rogers Pass summit produced 4, size 3.0 avalanches and 4, size 2.0-2.5.One natural avalanche was recorded yesterday, East of the summit, a small size 1.5, from a wind loaded start zone which ran to 2/3 path, on a North aspect.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Friday

Avalanche Problems

Persistent Slabs

Surface hoar layer buried 40-55cm. This layer is reactive to rider triggering and remote triggering and has been seen to be most reactive where the surface hoar is sitting on a sun crust or firm layer in the snowpack (bed-surface).

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Storm Slabs

Instabilities in the upper 50cm from the recent storm snow can step down to the Feb 12 surface hoar layer.

Be cautious as you transition into wind affected terrain.Test slopes before committing to them.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3