Avalanche Forecast

Issued: Apr 13th, 2017 8:25AM

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

ross campbell, Parks Canada

Glacier.

Still waiting for spring conditions! Unfortunately this leaves us in a low probability, high consequence conditions.

Summary

Weather Forecast

An unorganized weather pattern is upon us We could see 1cm to 10cm of snow above 1900m, winds are currently mod-gusting to strong from the NE, but are forecasted to switch to the SW today and stay in the Mod range. FL may hover near 1900m or could start cooling after lunch depending which forecast to believe.

Snowpack Summary

5cm of new snow overlies a series of crusts on most asp up to 1900m. Polar asp will be holding the best quality snow @ upper treeline and above. A snow profile on Mt Fidelity yesterday showed a HS of 325cm, snow was dry throughout and little to no results on snow pack tests.

Avalanche Summary

No new avalanche activity observed in the highway corridor yesterday (but we had poor visibility). TRU observed a natural cornice to size 2 in the Perley area and our neighbors are still observing large natural avalanches. Earlier in the week cornices were failing and a few storm slabs and loose wet slides to size 2.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

Moderate gusting to strong winds from the NE this morning and last night are building wind slabs in the alpine and at the upper end of treeline. Winds are forecast to switch today to the SW and stay in the moderate range.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Avoid lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

Storm slabs are most volatile where they overlie a crust on solar aspects. 50+cm of new snow accompanied by warm temperatures and wind fell over the last week in the alpine and upper end of tree line.

Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Cornices are always unpredictable! However we are seen cornices fail in the HWY corridor and in the back country on a semi regular basis. With naturals triggers easing, back country enthusiasts would be the likely trigger.

Minimize exposure to overhead hazard from cornices.Stay well to the windward side of corniced ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 14th, 2017 8:00AM