Avalanche Forecast

Issued: Feb 18th, 2018 4:25PM

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

shorton, Avalanche Canada

South Coast.

Triggering storm slabs is a concern at all elevations. Be very suspect around wind-affected slopes and convex terrain features.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

MONDAY: Clear and cold with moderate north wind and alpine high temperatures around -10 C.TUESDAY: Mostly sunny, light wind, alpine high temperatures around -10 C.WEDNESDAY: Mix of sun and cloud with isolated flurries, light wind, alpine high temperatures around -8 C.

Avalanche Summary

No new avalanches were reported on Sunday, but storm snow was very reactive on Saturday. Numerous size 1-2 slab avalanches were triggered by skiers on all aspects at treeline and below treeline, including some that were triggered remotely (from a distance).Looking ahead, avalanche activity is most likely in areas that have been loaded with the recent northerly winds, but any steep terrain feature is suspect given the widespread crust sitting beneath the storm snow.

Snowpack Summary

In sheltered terrain, cold weather is preserving 30-50 cm of low density snow. In exposed terrain, strong north winds have scoured north facing slopes and loaded south facing slopes. A hard rain crust that extends into alpine terrain is buried about 40 cm beneath the recent storm snow. Reports suggest the snow has not yet formed a strong bond to the crust, creating a potential bed surface for slab avalanches. Monitor the bond of the new snow to this crust closely in your local area. There are no significant layers of concern below the crust.

Problems

Storm Slabs

Strong northerly winds have formed fresh slabs at higher elevations. Triggering a slab above the buried crust remains a possibility at all elevations.

Use careful route-finding and stick to moderate slope angles with low consequencesUse caution above cliffs and terrain traps where small avalanches may have severe consequences.Be very cautious near open slopes and convex rolls

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Cornices

Large cornices have formed along ridgelines. Cornices are inherently unstable, unpredictable, and demand respect.

Give cornices a wide berth when traveling on or below ridges.Firm cornices may pull back into flat terrain at ridgetop if they fail.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 19th, 2018 2:00PM