Avalanche Forecast

Issued: Jan 4th, 2014 8:05AM

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

Catherine Brown, Parks Canada

Glacier.

As temperatures drop and skies clear, cornice fall is possible. Avoid exposure to these large triggers.

Summary

Weather Forecast

The skies will clear today after a stormy past. The forecast is for a mix of sun and cloud, alpine temps around -11deg C and NW 30-55 km/h ridge top winds. This pattern will continue through Monday, when the ridge weakens, temperatures start to size and a possible weak front reaches the park on Tuesday bringing light precip.

Snowpack Summary

We received 50 to 60 cm of storm snow in the last 48hrs at treeline. This storm had mild temp's and mod/strong winds from the W, creating very touchy storm slabs. Although this fell on a well-settled snowpack, the Nov 28 surface hoar/facet layers remain a concern. Avalanches could step-down to these layers with the new loading.

Avalanche Summary

On Thursday and Friday we observed a large natural avalanche cycle along the highway corridor. Avalanches were up to size 3.5 and reaching the end of the runnout. A notable size 3.5 from Mt. Tupper cleared out mature timber and deposited around 2 m of debris on the road for 125 m. The largest avalanches occurred on SE through SW aspects.

Confidence

Due to the number of field observations

Problems

Storm Slabs

40 to 60 cm of storm snow has formed slabs. These deposits will be deeper in areas with wind loading. Natural avalanches are still possible, assess terrain continually while you travel.

The new snow will require several days to settle and stabilize.Be wary of slopes that did not previously avalanche - even on low angle terrain.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Wind Slabs

Older wind slabs are buried on various weak layers below new storm snow. Use your pole to feel for this firm, wind-deposited snow in exposed areas. These slabs have the potential to fail with the new, heavy load.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Jan 5th, 2014 8:00AM