Avalanche Forecast

Issued: Feb 4th, 2016 9:24AM

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 jsmith, Avalanche Canada

Extra Caution required in alpine and open treeline features.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Moderate southerly winds Thursday night will redistribute storm snow.  10-15cm of snow with moderate to strong southwesterly winds on Friday.  Another 5-10cm on Saturday with light to moderate westerly winds.  No snow forecasted for Sunday and winds die down.  Freezing levels rise to 1300m on Friday, followed by a cooling trend.

Avalanche Summary

Several size one skier triggered avalanches were reported on Wednesday.  We expect the size and sensitivity of the storm slabs to increase on Friday.

Snowpack Summary

10cm of new snow brings the storm slab to 35-45 cm and can be found across most of the region. This new snow lies above a variable old surface buried at the end of January. This interface is being reported as a layer of surface hoar at treeline in the Rossland area. However, in most other parts of the region the new snow sits on a rain crust and/or old wind slabs. A weak layer buried mid-January can be found down 45-50cm, however, snow pit tests indicate that this layer is gaining strength. Deeper in the snowpack, the persistent weak layer that was buried earlier in January is now down 80-120 cm and continues to give sudden planar fractures in snowpack tests under moderate to heavy loads.

Problems

Storm Slabs

An icon showing Storm Slabs
Moderate winds, new snow and warming temperatures are expected to create touchy conditions as the new snow settles to form a slab
Be cautious as you transition into wind affected terrain.>Choose well supported terrain without convexities.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
This persistent weak layer is a classic low probability but high consequence problem. Dig down to see if the surface hoar exists in your area.
Dig down to find and test weak layers before committing to a big line. >Be aware of the potential for large avalanches due to the presence of buried surface hoar. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 5

Valid until: Feb 5th, 2016 2:00PM

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