Avalanche Forecast

Issued: Feb 22nd, 2014 8:04AM

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

catherine brown, Parks Canada

Glacier.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=15974&oPark=100205Enjoy the great skiing in the park today by making very conservative terrain choices and using good group management.

Summary

Weather Forecast

A cold, dry air mass moves into the region today staying in place for the forecast period. Expect a mainly cloudy day with alpine temperatures around -11 and light ridge top winds. Sunny skies with alpine temperatures below -15 are forecast for Sunday and Monday.

Snowpack Summary

1-1.4m of storm snow is settling into a cohesive slab over the Jan 28/22 facet/surface hoar/crust interface. Snowpack tests suggests this weak layer is difficult to trigger, but if failed has high propagation propensity. In addition, layers in the top 60cm of the storm slab are reactive and if triggered will likely step down to the Jan 28/22.

Avalanche Summary

Yesterday a few natural avalanches were observed along the highway corridor size 1.5 to 2. Close neighbours are reporting large skier triggered avalanches up to size 3. Less obvious signs of instability cracking, recent avalanches activity and whumphing are being observed while traveling but the buried weak layers remain reactive.

Confidence

Due to the number of field observations

Problems

Persistent Slabs

A strong slab overlies a very weak layer buried down 1-1.5m. The snowpack now demands your respect, if you trigger this layer a large, high consequence avalanche will result. Use caution in shallow snowpacks, where triggering is more likely.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Wind Slabs

Use caution as you transition into exposed terrain. Triggerable wind slabs may be present on lee features. If triggered these slabs may step down to trigger deeper instabilities.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Cornices

Yesterday, a slab 1-1.5 meters deep was observed that was triggered by cornice failure. Large cornices exist along ridges, and may fail with fluctuating temperatures and sunny periods. These are heavy triggers that could initiate BIG avalanches.

Do not travel on slopes that are exposed to cornices overhead.Pay attention to overhead hazards like cornices.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 23rd, 2014 8:00AM