Archived

Avalanche Forecast

Mar 13th, 2020–Mar 14th, 2020

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

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Sea To Sky.

Strong northeast wind has formed wind slabs on atypical aspects. Cold air may limit solar influence, but use caution if the snow moistens.

Confidence

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

Weather Forecast

FRIDAY NIGHT: Partly cloudy with isolated flurries, 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 -10 C.

MONDAY: Clear skies, light to moderate northeast wind, alpine temperature 0 C, freezing level rising to 2000 m.

Avalanche Summary

A few cornices were triggered by explosives on Friday. They did not trigger slabs on the slopes below, but did entrain some snow. Otherwise, small wind slabs were triggered naturally and by skiers. They were reported to be touchy but did not propagate far or produce thick slabs.

For the remainder of the weekend, it will 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.

Weak faceted snow and melt-freeze crusts exist near the base of the snowpack in some of the region, particularly the eastern and northern parts. This layer is considered dormant, as it hasn't produced an avalanche since February 20th. This layer may require a very large load, such as a cornice fall, or rapid weather changes to reactivate.

Terrain and Travel

Be carefull around freshly wind loaded features.
Recent wind has varied in direction so watch for wind slabs on all aspects.
Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.

Avalanche Problems

Wind Slabs

Wind slabs may be found on all aspects due to previously strong southwest wind switching to strong northeast wind. Northeast wind is atypical, so you may find wind slabs in terrain features that don't typically have them. These slabs could be touchy, as they may overly a weak layer of surface hoar. Use extra caution as you approach exposed terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2