Avalanche Forecast

Issued: Dec 29th, 2013 8:09AM

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

ali haeri, Parks Canada

Glacier.

Summary

Weather Forecast

We are in an unsettled weather pattern bringing light precipitation amounts for the next few days. Winds are forecast to pick up today from the north west gusting to 80km/h in the alpine.

Snowpack Summary

70cm of recent storm snow sits over a settling mid pack. Storm snow amounts are less east of the Rogers Pass summit. The December 8 surface hoar/facet layer is down 70-85cm and the November 28 surface hoar layer is down around a meter which is still well preserved in certain areas.

Avalanche Summary

Yesterday, natural avalanche activity produced slab avalanches to size 2.5 east of the Rogers Pass summit. Avalanche control took place yesterday in the western half of the highway corridor yesterday morning producing avalanches from size 2.0 to 3.0 as well as a sympathetic size 3.5.

Confidence

Problems

Wind Slabs

Strong winds are expected today with lots of snow available to be deposited onto adjacent slopes.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

The recent storm snow has instabilities within it that will need a few days to heal.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

The 2 buried weak layers down 70 to 110cm are still producing results in our snowpack tests. Caution around shallow snow pack areas where triggering these layers is most likely.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Dec 30th, 2013 8:00AM