Avalanche Forecast
Issued: Feb 22nd, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
cgarritty,
Avalanche Canada
Reports show this region leading the way with a sharp increase in avalanches after the storm. Use conservative slopes to assess conditions locally and make a plan to step back as winds pick up.
Summary
Confidence
High
Avalanche Summary
Wednesday's reports showed a rapidly settling 15-20 cm becoming increasingly reactive with daytime warming and yielding numerous skier-triggered avalanches to size 1 and naturals to size 2 in the MacGillivray Pass area. At least one size 2 was observed running on the persistent facet/crust layer from early February.
A report from the Hurley was less severe with dry loose releases transitioning to shooting cracks and small releases on isolated east aspects at treeline.
Snowpack Summary
15 - 20 cm of rapidly settling snow from the early part of the week has buried a variety of previous surfaces including a crust on south aspects, and all aspects at lower elevation, faceted snow and/or small surface hoar in sheltered features, and previously wind-affected surfaces in the open. Areas where wind loading has increased the depth of new snow and where larger preserved surface hoar is buried are the most concerning.
Roughly 40 - 50 cm of snow now sits above a widespread crust from late January. Weak grains like facets or more unlikely surface hoar may be found above this crust. This problematic layering remains a concern with new load above it.
Snowpack depths decrease rapidly below treeline.
Weather Summary
Thursday night
Cloudy. 15 to 20 km/h southwest alpine wind. Freezing level falling to 1300 m.
Friday
Cloudy. 15 to 25 km/h southwest alpine wind, increasing. Treeline temperature -2°C with freezing level around 1500 m.
Saturday
Cloudy with scattered flurries bringing less than 5 cm of new snow, including overnight amounts. 15 to 25 km/h southwest alpine wind. Treeline temperature -2 °C with freezing level to 1500 m.
Sunday
Cloudy with flurries bringing 5 - 15 cm of new snow, including overnight amounts. 40-50 km/h southwest alpine winds. Treeline temperature -3 °C with freezing level to 1400 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs are most reactive during their formation.
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Wind Slabs
Expect deep and reactive slabs perched in the lee of ridges and exposed terrain features, but be careful about ruling out steep terrain that hasn't been wind loaded. New snow isn't bonding well to the old surface.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Recent observations show the problematic early February layer of facets on crust becoming increasingly triggerable. Avalanches triggered on this layer will be destructive.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 23rd, 2024 4:00PM
