Archived

Avalanche Forecast

Nov 24th, 2017–Nov 25th, 2017

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

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

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

Regions: Kootenay Boundary.

Lookout for small wind slabs sitting on a hard crust in wind affected terrain at treeline and above. Due to limited data it is CRITICAL to supplement this information with your own observations. Please post your observations to the MIN.

Confidence

Low - Due to the number of field observations

Weather Forecast

SATURDAY: Cloudy / Light southerly ridgetop winds / Freezing level around 1500 mSUNDAY: 10-20 mm rain / Moderate to strong southwesterly ridgetop winds / Freezing level around 2500 mMONDAY: Cloudy with isolated flurries / Light to moderate westerly ridgetop winds / Freezing level around 1500 m

Avalanche Summary

On Thursday, no new avalanches were reported in this region. However, we currently have very limited observations in this region. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

A new crust was formed on Thursday as temperatures cooled and the rain soaked snow surface froze and then was covered by 5-10cm of snow at treeline and above. The depth of the snowpack varies greatly with elevation. Recent reports suggest the average depth is 100+cm in the alpine, 50-100cm at treeline, and decreasing rapidly below treeline where the primary hazards are rocks, stumps, and open creeks. Recent heavy rain to the mountaintops has rapidly shrunk the snowpack and has transitioned much of the snowpack from dry to moist snow. The major feature in the snowpack is a crust which was formed at the end of October can be found approximately 30cm above the ground. However, the new surface crust will temporarily reduce the likelihood of triggering on this layer. We currently have very limited snowpack observations within this region and it is critical to supplement this information with your own observations.

Avalanche Problems

Wind Slabs

Fresh wind slabs may have formed below ridgetops in areas where the precipitation fell as snow on Thursday afternoon.

Be cautious as you transition into wind affected terrain.Avoid areas which have been loaded by new snow and wind.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Persistent Slabs

Recent rain to mountaintops combined with overnight cooling Thursday night has reduced the likelihood of triggering this layer. Areas in which the snowpack above this layer remained dry should be treated with increased caution.

Avoid shallow snowpack areas where triggering is more likely.Use increased caution in areas which did not form a surface crust.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3