Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Nov 23rd, 2011–Nov 24th, 2011
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
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
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: Kootenay Boundary.

Confidence

Good - -1

Weather Forecast

Thursday will remain cloudy with precipitation starting back up in the afternoon and throughout the evening. Freezing levels will generally drop to around 900m. There may be short periods of dryer weather, and dropping freezing levels. Cooler, dryer weather is expected for Friday. Don't let this fool you, a "Pineapple Express" is headed towards the region bringing warmer temperatures, moderate-heavy precipitation, and strong south westerly winds. The brunt of this storm is likely to hit the region Saturday night.

Avalanche Summary

Observations are extremely limited at this time. There have been no recent avalanche reports from the region. I suspect a large natural avalanche cycle has occurred. Is it happening right now? If you have any input, or observations please email us at [email protected]. A high danger rating does mean that natural and human triggering are likely.

Snowpack Summary

In upper elevations an average up to 60cm of new snow has fallen in the southern part of the region creating storm slab instabilities. This has been accompanied by moderate to strong winds from the southwest which are responsible for forming new wind slabs in the alpine and at treeline below ridgelines and terrain features. At treeline I suspect there to be some patchy areas of buried surface hoar and older raincrusts buried lower in the snowpack potentially up to a meter deep. With very limited observations from the field I suspect these layers (if existing) will reach their threshold and become reactive. I sense these layers will either clean themselves out, or start a healing process as the warmer temperatures persist. Snowpack depths are likely in the 60-90cm range at about 1600m and up to 150cms at 2000m. This may be a good time to sit out the storms and let the snowpack settle.

Avalanche Problems

Storm Slabs

Heavy amounts of snowfall and warmer temperatures will persist over the next few days. This will likely create widespread avalanche activity all elevations. Storm slabs may be touchy, run far and be destructive.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1 - 4

Wind Slabs

Strong southwesterly winds will create new wind slabs on lee slopes and terrain features. These wind slabs may be found lower on the slope in unsuspected areas.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Likely - Very Likely

Expected Size: 1 - 4