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Avalanche Forecast

Jan 11th, 2017–Jan 12th, 2017
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
1: Low
The avalanche danger rating at treeline will be low
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
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Sea To Sky.

Wind slabs can currently be found on almost any aspect. Expect those on steep southerly slopes to be especially touchy.

Confidence

High - The weather pattern is stable

Weather Forecast

Thursday: A mix of sun and cloud with no new snow. Winds light from the west. Alpine temperatures to -8.Friday: Cloudy with sunny periods and no new snow. Winds moderate to strong from the west. Alpine temperatures to -4.Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Winds moderate to strong from the southwest. Freezing level rising to 800 metres with alpine temperatures to -3

Avalanche Summary

A MIN report from Tuesday details a skier triggered avalanche involvement in the adjacent South Coast Inland region. The avalanche was triggered in a rocky section of a steeper southeast-facing slope where there appeared to be evidence of recent wind loading. Tuesday's wind event resulted in numerous Size 1 wind slabs running naturally on steep southerly slopes. Natural avalanche activity was focused in areas that had more new snow available for transport by our outflow winds. Crown depths ranged from 15 cm up to 40 cm in heavier snow areas. Previous to this activity, observations on Monday revealed widespread soft slab activity (to Size 1.5) on northerly aspects with explosives and skier traffic.

Snowpack Summary

New snow from Sunday-Monday totalled 18 cm near Whistler while 25-35 cm fell in the upper Callaghan / Powder Mountain area. In the days since the storm, winds shifted to classic outflow (northerly) patterns with strong winds at ridge top. This resulted the new snow being 'reverse loaded' onto southerly slopes as wind slabs and soft slabs. These slabs are the primary weaknesses of concern in the snowpack and our colder-than-usual temperatures mean the upper snowpack will be slower than usual to heal. Deeper in the snowpack, the new snow from Sunday night and also last Friday is bonding fairly well to a variable surface consisting of a mix of soft wind slabs, hard wind slabs, sastrugi, faceted snow, and even some surface hoar. Snowpack layers below this interface are generally well bonded, and the lower snowpack is solid.

Avalanche Problems

Wind Slabs

Watch for soft slabs on sheltered northerly aspects, and touchy wind slabs on 'reverse loaded' southerly aspects. Expect stability on southerly aspects to deteriorate quickly with any solar radiation input.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution in lee areas. Recent wind loading has created wind slabs.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3