Archived

Avalanche Forecast

Feb 18th, 2018–Feb 19th, 2018

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast.

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

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.

Avalanche 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