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Avalanche Forecast

Jan 12th, 2018–Jan 13th, 2018
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
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: Northwest Inland.

Watch for touchy wind slabs that have formed from recent winds.

Confidence

Low - Due to the number of field observations

Weather Forecast

SATURDAY: Cloudy with light snowfall, accumulation 5 to 10 cm, light to moderate southwesterly winds, alpine temperature -2 C but colder in the valleys, freezing level below valley bottom with inversion conditions.SUNDAY: Mostly cloudy, moderate to strong southerly winds, alpine temperature near 2 C, inversion conditions with cold valley air and above-freezing level between about 1500 m and 2500 m.MONDAY: Mostly cloudy with intermittent precipitation, accumulation 1-3 mm, moderate to strong southerly winds, alpine temperature near 2 C, inversion conditions with cold valley air and above-freezing level between about 1000 m and 2500 m.

Avalanche Summary

Skiers were able to trigger pockets of wind slab on north-to north-west facing slopes on Tuesday and Wednesday.

Snowpack Summary

Variable winds have built slabs on many different slopes, primarily in the alpine but also in lee features at treeline. Recent snow (around 20-30 cm) overlies various surfaces including a freezing rain crust (which was reported as being hard in the alpine and breakable below treeline), old sun crusts and wind slabs.A variable weak layer that formed in mid-December can be found in the upper snowpack. This mid-December layer is comprised of crusts on solar aspects and feathery surface hoar in sheltered locations.The lower snowpack is generally well-settled with two prominent crusts. The late-November crust can be found 30-50 cm below the surface and the October crust is near the base of the snowpack.

Avalanche Problems

Wind Slabs

Recent winds from variable directions have formed wind slabs in lee features. Wind slabs are likely more widespread in alpine terrain.
Use ridges or ribs to avoid pockets of wind-loaded snow.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2