Avalanche Forecast

Issued: Feb 11th, 2018 4:53PM

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

mgrist, Avalanche Canada

South Coast.

Cooling temperatures have formed a thick crust that extends into the alpine. At upper alpine elevations pockets of wind slab may exist and will likely be poorly bonded to the underlying crust.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Tuesday

Weather Forecast

MONDAY: Sunny. Ridge wind light, northwest. Temperature -3. Freezing level 700 m. Alpine inversion.TUESDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind moderate, west. Temperature near -2. Freezing level 600 m. Alpine inversion.WEDNESDAY: A mix of sun and cloud with occasional flurries. Ridge wind light, north west. Temperature near 0 degrees. Freezing level 700 m.

Avalanche Summary

On Saturday, a cornice collapse was the likely cause of a size 2 avalanche on a north facing slope near the West Lion. See here for images and more details. Pockets of thin wind slabs may exist in wind-loaded areas in the high alpine and may be sensitive to human triggers.

Snowpack Summary

Rain at the end of the week saturated snow surfaces and only higher alpine elevations were lucky enough to receive a light cover of new snow. With the arrival of cold temperatures, the upper snowpack has locked up as a firm crust. The average snowpack depth at treeline is 300 cm of well settled snow with no significant layers of concern.

Problems

Wind Slabs

Wind slabs may have a poor bond to the underlying crust and be reactive at upper alpine elevations. Loose dry avalanches are possible from steep alpine terrain features.

Be careful with wind loaded pockets that may exist near ridge crests and roll-overs.Use caution above cliffs where small avalanches may have severe consequences.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Cornices

Large cornices have formed and may remain fragile. Cornices are unpredictable and demand respect. Give them a wide berth from above and below, especially during periods of warming temperatures or sun-exposure.

Give cornices a wide berth when traveling on or below ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 12th, 2018 2:00PM