Avalog Join
Archived

Avalanche Forecast

Feb 19th, 2016–Feb 20th, 2016
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
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

Regions: Northwest Inland.

Recently formed storm slabs and wind slabs will continue to be reactive to human-triggering. Conservative terrain selection remains very important.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday

Weather Forecast

Unsettled conditions continue, bringing a trace of new snow Friday night. On Saturday, freezing levels will fall to1000 m with a mix of sun and cloud. Alpine temperatures -4 and ridgetop winds will be moderate from the South. Sunday will be mostly cloudy with a trace of new snow. Alpine temperatures -5 and freezing levels 800m. Ridgetop winds will blow moderate-strong from the south. Monday will bring a mix of sun and cloud with alpine temperatures -7 and moderate-gusting strong winds from the West.

Avalanche Summary

On Thursday no new avalanches were reported. Earlier in the week smaller isolated storm and wind slabs were reported. If the sun comes out, natural avalanches are possible on steep south facing terrain features. In the far north, deeply buried persistent weak layers may still be reactive to large triggers such as a small avalanche stepping down or a cornice failure.

Snowpack Summary

Recent storm snow accumulations are 40-80cm over the past week and overlie a melt freeze crust which extends up to around 2000m elevation. This recent snow is reported to be bonding well to the crust. Moist snow was reported below 1200m on Wednesday and wet snow below 800m. Recent wind has redistributed the surface snow at higher elevations forming wind slabs in leeward features. The early January surface hoar/facet layer is down around 1m+ and remains a concern for commercial operations. This layer seems the most reactive in the north of the region but may still be a concern in the south as well. Shallow snowpack areas in the east and north of the region may have a weak base layer of facetted snow on or just above the ground.

Avalanche Problems

Storm Slabs

Recently formed storm slabs are expected to be reactive to rider triggering this weekend. Wind loaded alpine features and south facing slopes when the sun shines are likely to have the most reactive slabs.
Be alert to conditions that change with elevation. >Stay off recent wind loaded areas until the slope has had a chance to stabilize. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Deep Persistent Slabs

Buried weak layers are still reactive in the snowpack, especially in the far north of region, and have the potential to produce very large avalanches. Thin spot triggering, cornice releases, and smaller avalanches all have the potential to step down.
Be aware of the potential for large, widely propagating avalanches due to the presence of buried surface hoar.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 3 - 6