Avalanche Forecast

Issued: Nov 28th, 2017 4:04PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Persistent Slabs.

Avalanche Canada mgrist, Avalanche Canada

New snow and southerly winds will be driving avalanche danger on Tuesday into Wednesday. We have limited information so be prepared to modify your objectives based on local observations.

Summary

Confidence

Low - Intensity of incoming weather systems is uncertain

Weather Forecast

We're looking at a brief lull in the active weather pattern on Wednesday, before the next system arrives on Thursday with modest amounts of snow.WEDNESDAY: Cloudy with isolated flurries. Moderate to strong south westerly ridgetop winds. Freezing level around 1200 m.THURSDAY: Scattered flurries, 5-10cm snow during the day with 5-10cm possible overnight. Moderate southwesterly ridgetop winds. Freezing level around 1100 m. FRIDAY: Cloudy with sunny breaks during the day and isolated flurries. Moderate south west ridgetop winds. Freezing level around 1000 m.

Avalanche Summary

No new avalanches were reported in this region. A natural avalanche cycle is expected on Tuesday into Wednesday, especially where new snow may be falling on a crust formed November 27th. We currently have very limited observations in this region. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

Warmer temperatures on Sunday may have resulted in a crust (November 27th crust) up to treeline elevations, with up to 10cm of snow on top of this crust. At higher elevations, southerly winds (gusting strong at times) likely re-distributed the new snow, forming wind slabs on lee features, such as below ridgetops and in gullies. Lower down in the snowpack,10-25 cm snow from last weekend sits on the previous warm temperature crust from November 23rd. We haven't had much information on how well the snow is bonding to this crust.The depth of the snowpack varies greatly with elevation. Recent reports suggest the average depth is 200+cm in the alpine, 100-160cm at treeline, and decreasing rapidly below treeline where the primary hazards are rocks, stumps, and open creeks. A major feature in the snowpack is a crust which was formed around November 11th and can be found approximately 100cm down at treeline elevations. We currently have very limited snowpack observations within this region and it is critical to supplement this information with your own observations.

Problems

Storm Slabs

An icon showing Storm Slabs
A natural avalanche cycle is expected on Tuesday into Wednesday, especially where the new snow sits on a temperature crust that formed November 27th.
Use conservative route selection, choose moderate angled and supported terrain with low consequence.Watch for signs of instability such as whumpfing, cracking, or recent natural avalanches.Avoid exposure to avalanche terrain during periods of rapid loading by rain, snow, or wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
Rapid loading by rain or snow will increase the likelihood of avalanches occurring on the November 11 layer.
Avoid exposure to avalanche terrain during periods of rapid loading by rain, snow, or wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 29th, 2017 2:00PM