Avalanche Forecast
Issued: Dec 22nd, 2011 9:15AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to variable snopack conditions
Weather Forecast
Friday: Mixed skies, with southwesterly winds increasing to 30km/h through the day and highs of -6. Saturday: Continued southwesterly flow with flurries developing over the west side of the region. Freezing levels may reach 1600m. Sunday: A mix of sun and cloud, with a possibility of localized flurries. Continued southwest winds and freezing levels to 1600m.
Avalanche Summary
Avalanche observations have dramatically slowed, with minimal new observations. Reports show no new natural avalanches and small, human triggered slides. As the load increases through the weekend, the likelihood of triggering will go up. Threshold for human triggering will precede natural releases.
Snowpack Summary
A north-south split exists in this region at present as a result of the track of recent storms. Northern and western areas have seen up to 50 cm of recent storm snow, while areas further south have seen more like 20cm. This storm slab is reported to be upside-down, which means higher density snow sits on top of less dense snow. The storm slab sits above a well developed surface hoar layer from mid December, which has been reacting readily to snowpack tests and ski cutting. Additionally, remote-triggered avalanches have been reported on this layer, indicating it has a high potential for fracture propagation. All this info points to the same thing: Where the storm slab is sufficiently thick (in the order of 40 cm) and cohesive, conditions are ripe for slab avalanches. Lower in the snowpack, the mid-layers are well-consolidated and strong. Near the base of the snowpack there are a few layers that have the potential to wake up with a really big storm or very heavy loads (cornice drop). These include a surface hoar layer from early November, a crust/facet combo from October and the interface on steep glaciated terrain with snow that did not melt over the summer.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 23rd, 2011 8:00AM