Avalanche Forecast
Issued: Nov 27th, 2018 3:24PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Low - Due to the number of field observations
Weather Forecast
TUESDAY NIGHT: Flurries with moderate southwesterly winds.WEDNESDAY: Occasional flurries with some clear spells. Moderate southwesterly winds. Freezing level around 1400 m.THURSDAY: Dry with a mix of sun and cloud. Light southwesterly winds. Freezing level around 1200 m.FRIDAY:Â Â Dry with a mix of sun and cloud. Calm winds. Freezing level around 600 m.
Avalanche Summary
It's unlikely there was quite enough snow for much natural avalanche activity to have occurred during the storm on Monday or Tuesday. However, human-triggered avalanches will remain a concern on steep, smooth slopes for a few days after the storm ends. On Saturday, a large human triggered avalanche was reported in the South Columbia forecast region. The size 3 avalanche occurred on a steep, north aspect in the alpine and failed to ground, likely on the October crust. This avalanche is notable for the Purcells where we have a similar, but shallower snowpack than in the South Columbia, resulting in a higher possibility of impacting a weak layer near the ground. Find the MIN report here.
Snowpack Summary
Approximately 20 cm new snow fell in this area during the most recent storm, which will have been blown into wind slabs on exposed northerly and northeasterly slopes. In most places, there are two layers of feathery surface hoar being reported, one around 20cm below the surface and one around 35cm. One or both of these may be associated with a crust on south aspects. The most likely places to trigger one of these layers is in deeper snow areas in shady spots on smooth slopes. A final, prominent feature of the snowpack is a combination of a crust and underlying sugary, faceted snow found near the base of the snowpack. It may still be possible to release an avalanche on smooth slopes in the alpine.
Problems
Storm Slabs
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 28th, 2018 2:00PM