Avalanche Forecast

Issued: Nov 27th, 2014 7:45AM

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

Avalanche Canada Peter, Avalanche Canada

Rapid cooling should help stabilize the snowpack and lower the avalanche danger heading into the weekend.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Friday: Temperatures start to plummet early with freezing levels dropping to 500 m by mid-day. We could see a pulse of light snow (5 cm) in the afternoon. Winds ease. Saturday: Mainly sunny. The freezing level is at valley bottom. Winds are light to moderate from the NE. Sunday: Sun and cloud. The freezing level remains at valley bottom. Winds are light from the W-NW.

Avalanche Summary

Numerous loose wet and wet slab avalanches up to size 2 were reported near Whistler on Wednesday as temperatures spiked and rain started to fall. It's likely that natural activity continued overnight with the potential for larger slab avalanches at higher alpine elevations. Natural activity should taper off on Friday if temperatures cool as forecast.

Snowpack Summary

It's likely that wet snow continues to fall at higher elevations (above 2000 m). Below this elevation recent snowfall has probably been soaked by rain. As temperatures drop later this week I would expect a new crust to form, possibly with some fresh snow on top. An old snow surface of weak facets sitting on a crust is now down as much as 50-60 cm at treeline elevations and deeper in the alpine. Initial reports suggest this weakness is most pronounced slopes at upper treeline and lower alpine elevations. However, as we begin our forecasting season, we are working with limited information from the field. Check the bond of the snowpack at this level and take a cautious approach as new snow builds deeper above this layer.

Problems

Storm Slabs

An icon showing Storm Slabs
Rapid cooling should help stabilize the snowpack but be aware of the potential for triggering deep storm/wind slabs above 2000 m and small loose wet sluffs if we get a dusting of fresh snow on Friday. 
Choose conservative lines and watch for clues of instability.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Avoid travelling on ledges and cliffs where sluffing may have severe consequences.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Nov 28th, 2014 2:00PM

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