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

Avalanche Forecast

Dec 2nd, 2014–Dec 3rd, 2014
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
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
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
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: Purcells.

The storm ended last weekend, but large and destructive avalanches are still possible. Remain conservative in your terrain selection.

Confidence

Poor - Due to the number of field observations

Weather Forecast

A ridge of high pressure will maintain mainly dry conditions for Wednesday and Thursday. For both days, expect a mix of sun and cloud with very light flurries and alpine temperatures of about -9. Winds should be light to moderate from the northwest on Wednesday switching to light and southwesterly by Thursday. A moist and warm southwest flow will bring snowfall to the region late Friday with freezing levels creeping up to about 1500m.

Avalanche Summary

A widespread natural avalanche cycle to size 3 was reported to have occurred last Friday and into Saturday. Since then we have had no new reports of avalanche activity. This may speak more to a lack of observations rather than actual conditions.I suspect avalanche activity on these deep layers will be less frequent, although the potential consequences of a release continue to be severe.

Snowpack Summary

Remote wind data suggests 10-20cm of recently fallen snow may have been pushed into wind slabs in exposed terrain. Below this you'll likely find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. Reports of whumphing and remote triggering on these layers suggests a persistent weakness with the potential for large propagation and large avalanches.

Avalanche Problems

Persistent Slabs

Up to 100cm of recent storm snow overlies weak crystals which are most reactive at higher elevations. Remain conservative in your terrain selection and avoid steeper, unsupported planar slopes.
Good day to make conservative terrain choices.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Caution around convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 5