Avalanche Forecast

Issued: Feb 19th, 2018 4:38PM

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

shorton, Avalanche Canada

Sea To Sky.

The snow is heavily wind-affected. Stick to sheltered trees to find the best and safest riding.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

TUESDAY: Sunny, light north 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. THURSDAY: Mostly sunny, 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.Triggering wind slabs will remain possible throughout the upcoming week.

Snowpack Summary

In exposed terrain, strong north winds have scoured north facing slopes and loaded south facing slopes. In sheltered terrain, cold weather is preserving 30-40 cm of low density snow. 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.

Problems

Wind Slabs

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

Sheltered slopes at lower elevations will offer the best riding.Approach steep lee and cross-loaded slopes with caution.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Cornices

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

Minimize overhead exposure to cornices above.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.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Feb 20th, 2018 2:00PM