Avalanche Forecast
Issued: Mar 29th, 2012 10:43AM
The alpine rating is Loose Wet, Wind Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to variable weather conditions
Weather Forecast
A continued low over the Gulf of Alaska will whirl a series of convective systems through the southern part of the province, bringing light precipitation to the North West regions. Friday: Snow amounts 5-15 cm. Ridgetop winds light from the SW. Alpine temperatures near -4. Freezing levels 900 m then falling to valley bottom at night. Saturday/Sunday: The weekend will continue with quite the mixed bag of unsettled, spring-like convective weather. Expect bands of fast moving clouds, light precipitation, and periods of sun in the afternoons. Freezing levels 500- 800 m during the day, falling to valley bottom at night. Ridgetop winds will be light - moderate from the SE.
Avalanche Summary
On Wednesday numerous point releases, and wet slab avalanches were reported. These occurred on isolated steep south aspects, up to size 2.5 below treeline elevations. Natural glide crack, slab releases also occurred below treeline up to size 3. Avalanche control with the use of explosives triggered several size 2-3 glide slabs, below 1000 m. The snowpack below treeline will remain unstable until the region receives a good re-freeze. Unsettled weather conditions are forecast. It's important to pay attention to weather, and it's influence on the snowpack when recreating in your local mountains. I suspect the period will be fairly cloudy, but if periods of sun shine through, beware of solar aspects.
Snowpack Summary
Moderate to strong southeast winds have created wind slabs on opposite slopes and terrain features in the alpine, and treeline. Spring-like conditions have existed over the past several days forming crusts on solar aspects at all elevations that become moist under sunny skies during the day. Melt conditions exist on all aspects below 1000 m, with no significant re-freeze. This has developed a well settled upper snowpack with no significant layers of concern. New surface hoar growth up to 10 mm has been reported on sheltered North aspects. Forecast snow may initially have a poor bond to these new surface forms (crusts, surface hoar). Below all this, down 60-120 cm exists a very spotty surface hoar/ facet interface. Operations from the field noted no recent activity on this layer. I suspect it's becoming dormant, but would be suspicious of large triggers like cornice fall, or under the weight of a sled and it's rider in specific areas. Cornices in the region are reported to be very large and potentially unstable.
Problems
Loose Wet
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 30th, 2012 9:00AM