Avalanche Forecast

Issued: Mar 13th, 2020 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

Expect to find wind slabs in atypical terrain due to northeast wind. Cold air may limit the effect of the sun, but still apply caution if the snow surface moistens.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

FRIDAY NIGHT: Partly cloudy with flurries in the south of the region, accumulation 2 cm and local amounts of 10 cm possible, moderate to strong northeast wind, alpine temperature -16 C.

SATURDAY: Clear skies, moderate northeast wind, alpine temperature -15 C.

SUNDAY: Clear skies, light to moderate northeast wind, alpine temperature -11 C.

MONDAY: Clear skies, light to moderate northeast wind, alpine temperature -2 C, freezing level rising to 1800 m.

Avalanche Summary

No new avalanches were observed on Friday. A recent wind slab avalanche was observed on Thursday, as seen in this MIN

It may be possible for humans to trigger wind slab avalanches as fresh wind slabs form from strong northeast wind.

Snowpack Summary

Wind slabs may be found on all aspects due to variable wind directions. Recent wind has blown from the northeast, forming fresh wind slabs in south to southwest terrain features at higher elevations. In sheltered terrain, about 30 cm of snow may overly a melt-freeze crust and potentially small surface hoar crystals in isolated features.

In the northern part of the region (i.e., Duffey/Hurley/Gold Bridge), a deep instability may linger at the base of the snowpack. It has not produced an avalanche since February 17th. Human-triggering is unlikely, though if one were to trigger the layer, it would likely be in a thin, shallow, rocky spot. A large load, such as from a cornice fall, or sustained warm temperatures have the potential to trigger this layer.

Terrain and Travel

  • Be aware of highly variable recent wind loading patterns.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind from variable directions has likely formed wind slabs on all aspects. The most recent wind has been from the northeast, meaning you may find wind slabs in atypical terrain features. Fresh slabs could form quickly on Saturday with new snowfall in the south of the region. Use caution as you enter wind-affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

In the north of the region (e.g. Duffey, Hurley, Goldbridge), a deep persistent weak layer of faceted grains near the ground presents a lingering concern on steep, shallow slopes in the alpine.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Mar 14th, 2020 5:00PM