Avalog
Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Register
Login
Archived

Avalanche Forecast

Jan 17th, 2013–Jan 18th, 2013
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
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
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 Coastal.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Overnight Thursday and Friday: Moderate snowfall (heavy in the north) becoming light on Friday / Strong to extreme southwest winds becoming moderate and northwesterly / Alpine temperatures at about -4.0Saturday: Light snowfall / Moderate southwest winds /  Alpine temperatures at about -2.0Sunday: Trace amounts of new snow / Light southwest winds / Alpine temperature of about -2.0

Avalanche Summary

Due to inclement weather observations have been very limited; however. numerous moist or wet snow avalanches to size 2 were reported from the region on Wednesday. They occurred as loose snow avalanches or as glide cracks, and released on a variety of aspects at treeline and below. I would suspect a sharp increase in windslab activity with weather forecast for Thursday night.

Snowpack Summary

Rain below treeline has maintained moist snow at lower elevations.  Moderate amounts of new snow (heavy amounts in the north) are likely to exist as new windslabs at treeline and above. A persistent weakness of surface hoar or facetted snow buried at the end of December sits below all of the more recent storm snow and is still on the radar of professionals in the area. The mid and lower snowpack are generally well settled and strong, although well developed basal facets remain a concern in shallow snowpack areas.

Avalanche Problems

Wind Slabs

Strong to extreme westerly winds continue to create touchy hard and soft wind slabs in exposed lee and cross-loaded terrain at higher elevations. Higher snowfall accumulations are forecast for the northern part of the region.
Be aware of the potential for wide propagations due to the presence of hard windslabs.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood: Likely - Very Likely

Expected Size: 1 - 4

Loose Wet

Rain at lower elevations is maintaining a weak snowpack. Watch for triggering in steep start zones.
Watch for wet loose or slab activity with forecast rain and/or warm temperatures.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Likely

Expected Size: 1 - 4

Persistent Slabs

Heavy loading by new snow and wind may overload the late December persistent weakness and result in large and destructive avalanches.
Be aware of the potential for large avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 3 - 6