Avalanche Forecast
Issued: Feb 14th, 2016 8:06AM
The alpine rating is Wind Slabs, Cornices and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Low - Timing, track, or intensity of incoming weather system is uncertain on Monday
Weather Forecast
Light snowfall is expected to continue Sunday overnight before a weak ridge of high pressure dries things out briefly on Monday morning. However, the southern part of the region may see enhanced snowfall Sunday overnight and Monday due to a storm tracking through Washington. The next substantial storm system is then expected to reach the south coast on Monday afternoon or evening. 5-10cm is possible Monday afternoon with freezing progressively climbing to around 1800m by Monday night. Another 20-30cm is forecast for Monday overnight with strong southwest winds in the alpine. Tuesday is forecast to be mainly dry with light alpine winds and afternoon freezing levels around 1500m. A weak storm system is forecast to arrive on Wednesday with freezing levels around 1800m.
Avalanche Summary
On Saturday, a ski cut produced a size 1 slab avalanche in a leeward feature on a northeast aspect at 2200m. The slab was 10-20cm thick. On Friday, ski cuts produced size 1 loose wet avalanches at treeline in the recent storm snow. Rain-soaked lower elevations are unlikely to see much in the way of avalanche activity, but wind slab avalanches will continue to be reactive to human-triggering at higher elevations with ongoing snowfall and wind continuing overnight Sunday. Cornices are reported to large and fragile, and may fail under the weight of a person. Deeply buried persistent weak layers may still be reactive in the region but would probably take a heavy trigger like a cornice fall or smaller avalanche stepping down to cause a deep failure.
Snowpack Summary
Recent snowfall and mostly southwestern winds have formed wind slabs in the leeward features in the alpine and at treeline. High freezing levels (around 1800 metres) has settled the upper snowpack and developed variable crusts due to overnight cooling. New surface hoar has been reported from the Coquihalla area, that may be buried down 20-30 cm. Conditions across the region are variable. Most areas have not had a freeze below treeline since the last wet storm. A crust that formed after a warm storm at the end of January is now down 50-80 cm. and it does not appear to "bridge" the early January weak layer in the Duffey lake area. This deeply buried persistent weak layer from early January appears to be isolated to the north of the region, and is now buried down about 50-80 cm. This layer continues to produce sudden results in snowpack tests and has been responsible for recent destructive avalanches.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 15th, 2016 2:00PM