Avalanche Forecast

Issued: Dec 8th, 2012 8:05AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Dry, Wind Slabs and Storm Slabs.

Parks Canada Catherine Brown, Parks Canada

Sluffing in steep terrain is the main hazard today.  Pay attention to the sun if it comes out today.. and watch for warming on steep S-SW slopes this afternoon. 

Summary

Weather Forecast

A ridge of high pressure drives a cool NW flow for the next few days.  Valley cloud is possible with strong solar inputs above. High diurnal temperature change is expected.  Light snow is forecast Sunday and Monday.

Snowpack Summary

Cooler temperatures over the last 3 days have deposited a layer of light powder. Nov28 layer down 70 cm will be most reactive where it overlies a crust on steep S-SW slopes in the alpine or where surface hoar was buried; sheltered areas at treeline. The Nov 6 crust down ~150 cm is breaking down with mixed forms and facets present around Crs.

Avalanche Summary

No new avals were observed in the last two days along the highway corridor.Wednesday, a natural avalanche cycle occurred with, 1 size 3.5 and 2 size 2-2.5 avalanches observed from paths adjacent to the highway, east of Rogers Pass.  Avalanche started in steep terrain east of the summit, with some depositing snow at the end of runnout.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Loose Dry

An icon showing Loose Dry
In the past 3 days 40 cm of loose dry snow has fallen.  Expect this snow to move when traveling on steep slopes.  Be aware of other parties above and below you and manage your travel accordingly.
Be cautious of sluffing in steep terrain.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

Wind Slabs

An icon showing Wind Slabs
Strong S-SW winds have deposited wind packed snow on various terrain features.  Buried wind slabs have been observed in the park, use your ski pole to feel for these when transitioning into open terrain.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs
A weak layer down around 65 cm is starting to react less in stability tests.  Rider-triggering is still possible.  Use caution on steep slopes facing SW-W in the alpine where a buried thin sun crust identifies the weak layer.
Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Dec 9th, 2012 8:00AM