Avalanche Forecast
Issued: Jan 13th, 2017 4:33PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeWind effect is the critical factor. The safest, best riding may be in lower elevation terrain sheltered from the wind.
Summary
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
The dominating arctic airmass will linger through the weekend with continued cold temperatures at valley bottom and a strong alpine inversion, mostly cloudy skies with some sunny periods. Saturday/ Sunday/ Monday: Mix of sun and cloud with an alpine high near -8. Ridgetop winds light from the West. Check out the full synopsis here: http://www.avalanche.ca/weather/forecast
Avalanche Summary
On Thursday, wind slabs up to size 1 were easily triggered by the weight of a person. Variability in the winds has been the name of the game and reactive wind slabs may be found on all aspects at upper elevations.
Snowpack Summary
Up to 20 cm of recent snow has buried a variety of old snow surfaces. These consist of heavily wind scoured areas and old wind slabs, surface hoar in sheltered areas, and widespread faceted (sugary) old snow. Recent moderate winds from a variety of directions has redistributed some of this new snow on leeward slopes, forming reactive wind slabs. The mid pack appears to be quite variable throughout the region and the structure is dependent on snow depth. 50-80 cm of consolidated snow sits above the mid-December facets. In deeper snowpack areas, the snowpack appears to be well settled and right side up with isolated concerns for the mid-December weak layer. In shallow snowpack areas and lower elevations, the snowpack is heavily faceted and there are concerns for the mid-December weak facet layer as well as weak basal facets. If a persistent slab is triggered from thinner snowpack areas it may release on the basal facets (full depth avalanche). At this point it seems like a low probability, high consequence scenario. However; once the snowpack starts to see a big change, like warming then the likelihood of triggering may increase.
Problems
Wind Slabs
Recently formed wind slabs may still be reactive to human triggering. Changing wind directions may build wind slabs on all aspects.
Avoid areas where the surface snow feels stiff or slabby.Use ridges or ribs to avoid pockets of wind loaded snow.Watch for signs of instability such as whumpfing, or cracking.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Where stiffer snow overlies weak, sugary snow, there is the potential to trigger large, destructive avalanches.
Danger exists where denser snow overlies weak, sugary snow below.Be aware of the potential for full depth avalanches due to deeply buried weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 14th, 2017 2:00PM