Avalanche Forecast
Issued: Nov 30th, 2021 5:49PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Deep Persistent Slabs and Loose Dry.
Brian Webster,
A significant storm is expected on Wednesday. It will be best to enjoy the ski hill and avoid all avalanche terrain.
Summary
Weather Forecast
Wednesday will be a crux day for avalanches. 40-100 cm of snow is forecasted by end of day (more snow along the divide). This snow will be accompanied by very strong winds, high freezing levels and rain at lower elevations. Thursday will see convective flurries and clearing skies overnight. Freezing levels will drop to valley bottom.
Snowpack Summary
30-60 cm recent storm snow is reacting as a storm slab in alpine and tree-line locations. A crust (Nov 15) exists in the mid-pack in most areas below 2100 m. The Nov 5 crust/facet layer exists near the ground. Snowpack depths at tree-line average 80-100 cm. Lower elevation snow (below 1600 m) is rain soaked and isothermal.
Avalanche Summary
Natural and explosive triggered storm slabs have been observed at tree-line and alpine locations in past 48 hours. Many upper elevation storm slabs are stepping down to the deep persistent layer making for large class three avalanches. At lower elevations (below 1700 m) debris is gouging into isothermal snow and again making for large avalanches.
Confidence
Problems
Storm Slabs
40-100 cm of new snow and strong winds will create storm slabs at all elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
With a significant new snow load we expect to see larger and more frequent avalanches occur on the basal crust and facets. These avalanches have potential to run full path.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
Significant storm snow on Wednesday will create wide spread loose snow avalanches at all elevations.
Rain and warm temperatures below 2000m has potential to create loose moist avalanches as well.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 1st, 2021 4:00PM
