Avalanche Forecast

Issued: Jan 1st, 2017 4:11PM

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

Avalanche Canada jfloyer, Avalanche Canada

Cold north winds have been blowing. Watch for fresh wind slabs, particularly on southerly aspects.

Summary

Confidence

High -

Weather Forecast

MONDAY: Dry and sunny. Winds northeasterly 20-30 km/h at ridgetop. Ridgetop temperatures around -15C. TUESDAY: Dry and sunny. Winds northeasterly 20-30 km/h. Temperatures around -16C. WEDNESDAY: Dry and sunny. Winds northeasterly 40-60 km/h. Temperatures around -12C.

Avalanche Summary

Small wind slab avalanches could be triggered in recently loaded pockets up to size 1.

Snowpack Summary

The critical part of snowpack analysis under current conditions is figuring out how the wind is redistributing snow into wind slabs. Extreme northerly winds have been reported, which will be "reverse loading" wind onto slopes that were previously scoured. I suspect the cold will temper the reactivity of wind slabs on moderate slopes; however, on steep, aggressive terrain, particularly on south-facing slopes in the sun, wind slabs will definitely be in play. Between Monday and Friday last week, 70-100 cm of storm snow accumulated in the region. Below the new snow from this week lies the Boxing Day interface which consisted of wind affected surfaces, faceted (sugary) snow, or surface hoar. Recent observations suggest the overlying snow is generally well bonded to this interface. The mid-December interface is now down 100-150 cm and is generally considered to be stable in this region. Snowpack layers below this are well bonded.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh wind slabs have formed on mainly southwest to east aspect slopes in response to extreme northerly winds. Slabs found on south aspect slopes could become more unstable when the sun is out.
Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Carefully evaluate steep lines for wind slabUse safe ski cutting techniques before entering steep lines.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 2nd, 2017 2:00PM