Archived

Avalanche Forecast

Dec 19th, 2014–Dec 20th, 2014

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

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

Regions: Glacier.

Skiing is improving with new snow, but early season hazards remain at lower elevations. Buried surface hoar layer is becoming the main concern with increasing snow load. Watch out for fast moving natural and skier triggered sluffs in steep terrain.

Weather Forecast

Ongoing flurries amounting to 5cm of snowfall with moderate SW winds are expected throughout the day. A short lived ridge moves in later tonight to bring mostly dry conditions for Saturday morning. Early saturday evening, winds increase with a second pulse of precipitation bringing up to 10cm of snow by Sunday and 20cm for early next week.

Snowpack Summary

10-20cm of new snow has buried large surface hoar which sits on a rain crust to 2100m and on settled snow above 2100m. This is the most reactive layer in the snowpack. Surface hoar that was buried in early Dec is down ~40cm, is spotty in distribution. Well settled mid-pack with 30cm crust/facet basal weakness (Nov 9).

Avalanche Summary

No new avalanches were observed yesterday.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Avalanche Problems

Loose Dry

10-20cm of new snow will be quite reactive on a buried surface hoar layer, especially in steep terrain. Expect natural and skier triggered sluffing. Watch out for slab formation when warm temperatures, strong winds and additional snow arrive.

Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1 - 2

Persistent Slabs

The November crust weaknesses at the bottom of the snowpack are difficult to trigger, but if they fail the consequences will be very high.

Avoid shallow snowpack areas where triggering is more likely.Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely

Expected Size: 2 - 3