Avalanche Forecast
Issued: Nov 20th, 2011 3:00PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Due to limited field observations
Weather Forecast
Moderate precipitation amounts and light to moderate southwest winds are forecast for the interior during the day on Monday. The winds are then forecast to increase in the alpine with gusts to strong from the southwest overnight and into the morning Tuesday. There is a possibility that some up-slopes areas like the west monashees may see heavier than forecast precipitation amounts in the area of 20-30 cms of snow. The snow is forecast to continue through Wednesday with higher precipitation amounts forecast for the areas south of the Trans Canada Highway.
Avalanche Summary
A cycle of natural avalanche activity was observed in Quartz Creek on Sunday the 13th. Wind slabs (20cm deep) and persistent slabs (60cm deep) were observed. Persistent slabs were propagating widely and running on a weakness towards the base of the snowpack. Observations are limited to the northern Purcells so I don't know if this kind of thing is still occurring here. We have no new reports of new avalanches.
Snowpack Summary
There is significant variability in the snowpack across the region. Snowpack depth at treeline varies from around 40-130cm. Up to 50cm of snow fell late last week and over the weekend, which was redistributed by strong winds blowing first from the south and then from the north-west. A basal layer of facets was reported in the Dogtooth Range, with a weak interface between the lower facets and recent storm snow. Cold temperatures should cause continued facetting on the surface and in the basal layers.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 21st, 2011 8:00AM