Avalanche Forecast
Issued: Jan 24th, 2017 4:33PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeUncertainty with regards to the new storms forecast to hit the coast over the next few days. Stay tuned for more information regarding the developing avalanche danger this weekend.
Summary
Confidence
High -
Weather Forecast
Overcast with flurries or light snow combined with increasing southwest wind overnight. Freezing level around 500 metres on Wednesday with moderate southwest winds and 5-10 cm of new snow (more snow nearer to the coast). Another 5-8 cm of new snow by Thursday morning and 5-10 cm more during the day combined with strong southerly winds and freezing levels rising up to 1300 metres. Snow continuing on Friday with strong to extreme south winds and freezing levels around 1500 metres. The weekend also looks wet and windy, and some models suggest that heavier precipitation may arrive by Friday.
Avalanche Summary
No new avalanches reported from skiable terrain in the south. Some natural windslabs continue to release in the Bear Pass alpine up to size 1.5 in steep terrain. Triggering wind slabs as well as lingering persistent slabs remains a possibility at higher elevations.
Snowpack Summary
Light flurries and moderate winds have formed fresh wind slabs above 40-60 cm of settled storm snow from last week. Freezing levels reached 1200 m during the storm, which has left a hard supportive crust at lower elevations. At this point there is some uncertainty as to how deeper persistent weak layers are responding to the recent loading and warming. Several weak surface hoar and facet interfaces were reactive during the storm, but have shown signs gaining strength since. This includes the January 5th layer about 50 cm deep and the December 25th layer up to a metre deep. These are not typical conditions for this coastal region, and it will take more time to gain confidence about the distribution and likelihood of triggering these deeply buried weak layers.
Problems
Wind Slabs
Lingering wind slabs are expected to remain reactive to human triggering in steep wind loaded terrain features.
Use caution on open slopes and convex rolls If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Use ridges or ribs to avoid pockets of wind loaded snow.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
It may still be possible to trigger avalanches on buried weak layers (Dec 25, Jan 5th, Jan 12th surface hoar) ...or have a smaller avalanche 'step down' and trigger one of these layers.
Be aware of thin areas that may propogate to deeper instabilites.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. Assess start zones carefully and use safe travel techniques.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 25th, 2017 2:00PM