Avalanche Forecast
Issued: Feb 9th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
LP,
Avalanche Canada
The natural avalanche cycle is tapering after receiving 30 cm of new snow followed by extreme SW winds this week. We expect the sensitivity of the windslab problem to improve through the weekend, trending from likely to possible for human triggering.
Summary
Confidence
Avalanche Summary
Field staff did an avalanche patrol on Thursday and found several size 1.5 windslabs had released on lee loaded North through East aspects in the alpine. Last week, a skier on Forum Ridge reported triggering a size 1.5 slab with no involvement which apparently ran on the mid-January crust. This layer remains a concern with the recent new load.
Snowpack Summary
30 cm of storm snow from Tuesday night with extreme winds on Thursday has created fresh windslabs at treeline and above or on steeper exposed slopes below treeline. This brings the treeline snow depth to 50 cm overlying the thick January melt freeze crust that exists up to 2400 m. We are starting to see weak crystals develop above the crust and are monitoring this interface of concern.
Weather Summary
Extreme SW winds should ease Friday evening to more moderate values for Saturday before cranking up again for Sunday as the next system moves into the area. For Friday & Saturday, alpine temperatures will be in the -2 to -13C range. On Sunday freezing levels climb to 2000 m with the passage of a warm front where light rain may occur at lower elevations.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
30 cm of new snow on Tuesday has been blown into fresh windslabs by extreme SW winds on Thursday. The recent and older wind slabs overlie a thick rain crust where we are seeing sudden collapse results in field tests. The natural windslabs avalanche cycle may decrease over the weekend, but it remains likely for human triggering in steep terrain. If triggered they may step down to the January rain crust layer resulting in larger avalanches.
Aspects: North, North East, East, South East, South, North West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 10th, 2023 4:00PM
