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

1: Low

The avalanche danger rating below treeline will be low

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

1: Low

The avalanche danger rating below treeline will be low

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: Sea To Sky.

Wind slabs at higher elevations are the primary concern. Sheltered trees offer the best and safest riding.

Confidence

High - The weather pattern is stable

Weather Forecast

MONDAY: Sunny with moderate north wind and alpine high temperatures around -12 C.TUESDAY: Mostly sunny, light wind, alpine high temperatures around -12 C.WEDNESDAY: Mix of sun and cloud with isolated flurries, moderate north wind, alpine high temperatures around -10 C.

Avalanche Summary

Several small wind slabs (size 1) were reported in alpine terrain on Sunday, including a few that ran on buried sun crusts that were up to 60 cm deep on west and south aspects. The wind slabs were reactive to skier and explosive triggers.More widespread avalanche activity was reported during the storm on Saturday, including many size 1 skier-triggered slabs and a few size 2 natural slabs out of alpine terrain.

Snowpack Summary

In sheltered terrain, cold weather is preserving 30-40 cm of low density snow. In exposed terrain, strong north winds have scoured north facing slopes and loaded south facing slopes. A crust layer can be found beneath the storm snow on sun-exposed slopes and below 1900 m, which has supported some wide propagations in recent storm slab avalanches. Deeper in the snowpack, avalanche professionals are still monitoring the mid-January crust. This layer is now 150-200 cm deep, but a heavy trigger (cornice?) or the next major storm could potentially wake up this layer.

Avalanche Problems

Wind Slabs

Strong winds from the north have blown recent snow into touchy slabs at higher elevations.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Approach steep lee and cross-loaded slopes with caution.Sheltered slopes at lower elevations will offer the best riding.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Large cornices have formed along ridgelines. They need to be given an extra wide berth from above and below.

Falling cornices may trigger large avalanches on the slopes below.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Minimize overhead exposure to cornices above.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2.5