Avalanche Forecast
Issued: Dec 18th, 2011 9:06AM
The alpine rating is Wind Slabs and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Intensity of incoming weather is uncertain on Monday
Weather Forecast
Snowfall amounts for monday are highly uncertain, but some models are calling for 20-30cm on the west side of the region. Expect moderate to strong wind values and freezing levels between 500-1000m.On tuesday expect light to moderate snowfall with light westerly winds in the morning with clearing late in the day. Forecast freezing levels at about 300m.Clearing is forecast for wednesday with light to moderate southwest winds and freezing levels at surface.
Avalanche Summary
On saturday evidence of a size 2 natural avalanche cycle was reported in the Hankin area. There was also human triggering to size 2.5 in the same area. It is thought that these slides are releasing on the crust/surface hoar/facet interface. Forecast weather is uncertain for monday. If precip values are on the high side, expect another spike in natural avalanche activity for the region.Any information (professional or recreational) from the field is highly appreciated. Please send your observations to forecaster@avalanche.ca.
Snowpack Summary
Over the past week the region has received approximately 40cm of snow that now sits on a variety of weak snow surfaces (melt-freeze crust, surface hoar above the crust and facetted snow below the crust) that are a result of rain and then the early December dry spell. This crust is widespread and is lingering in most start zones up to 2000m. The recent winds in the alpine seem to have destroyed the surface hoar in exposed areas in the alpine possibly eliminating that issue, but creating a wind slab problem. In short, the upper snowpack is variable and showing easy shears in test results. A cautious approach is required as monday's forecast calls for new slabs to continue to form over the buried weak layers. The midpack seems to be well settled and strong.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 19th, 2011 8:00AM