Avalanche Forecast
Issued: Jan 21st, 2015 7:49AM
The alpine rating is Persistent Slabs, Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain on Saturday
Weather Forecast
Thursday: Flurries. Freezing levels rising to around 1400 m. Ridgetop winds 40-50 km/h from the southwest. Friday: Light precipitation in the afternoon that might fall as rain or snow. Freezing levels between 1800 and 2200 m, ridgetop winds rising to 70 km/h from the southwest. Saturday: light to moderate rain/snow in the 5-10 mm/cm range with freezing levels rising to around 2000 m. strong southwesterly winds.
Avalanche Summary
Numerous natural and human-triggered avalanches were reported to have run during and after the most recent storm, up to and including Tuesday 20th, which is the most up-to-date info at the time of writing. Noteably, those that occurred on Tuesday 20th were larger than those that were reported during the storm, and more likely to have been human-triggered (although natural avalanches were also reported from Tuesday). One very large natural avalanche was reported from an east aspect at 2700 m. We do not have any details about the layer this avalanche ran on. Most avalanches
Snowpack Summary
Between 30 and 50cm of new snow fell during the most recent storm over the weekend. It was distributed by strong winds into deeper, more cohesive deposits in higher wind-exposed terrain. A weak layer that comprises feathery surface hoar crystals up to 15 mm lies directly below the recent storm snow and sits above a crust in many areas, especially on south-facing slopes. This "mid-January" weak layer is widespread and has been the main focus for most of the recent avalanche activity. It has also been consistently producing easy "pop" type failures in snowpack tests.The still problematic mid-December surface hoar/crust layer is now buried anywhere from 60 to 110cm below the surface and continues to produce clean shears at and below treeline. Avalanches were reported to have stepped down to this layer during and after the most recent storm cycle. Although it has become less likely to trigger, I'd continue to treat this layer with respect and suspicion, particularly in the 1700-1900 m elevation band. A release on this layer would have very high consequences.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 22nd, 2015 2:00PM