Avalanche Forecast
Issued: Dec 24th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Storm Slabs and Persistent Slabs.
dsaly,
Avalanche Canada
Avalanche hazard will remain elevated with continued precipitation, strong wind, and rising freezing levels.
Summary
Confidence
Avalanche Summary
This MIN from Saturday documents a small skier-triggered avalanche and a natural slab avalanche in the Callaghan Lakes area.
Early reports Saturday documented wet loose avalanches up to 1700 m.
On Friday, explosives triggered size 1-1.5 slab avalanches up to 30 cm deep.
Please continue to post your observations and photos to the Mountain Information Network.
Snowpack Summary
In the last 48 hours, 30-45 cm of new snow covered a layer of weak and unconsolidated snow produced by the recent cold weather. Steady southwest winds have produced deeper depositions around ridges and in wind-loaded terrain. Rain and rising freezing levels have turned snow moist at lower elevations.
A number of layers persist deeper in the snowpack, consisting of facets, surface hoar, and crusts. Most recently, these layers have been unreactive and this heavy load of new snow should provide insight into any deeper instabilities. Total snow depths are roughly 90-140 cm at treeline and up to 200 cm in the alpine.
Weather Summary
Saturday night
Flurries, 5 cm. Ridgetoplow temperature -4 C. Southwest wind 25-35 km/hr. Freezing level 1000 m.
Sunday
Continued precipitation and rising freezing levels will produce a variety of frozen water forms including freezing rain at roadside elevations.
Flurries and wet snow transitioning to rain, 10 mm. Ridgetop high temperature 0 C. Southwest wind 30-60 km/hr. Freezing level rising above 2000 m.
MondayHeavy rain with freezing levels spiking above 2500 m, 25 mm overnight and another 15 mm through the day. Ridgetophigh temperature +2 C. South wind 50-70 km/hr.
TuesdayWet flurries transitioning to snow: 12 mm overnight and another 15 mm through the day. Ridgetop low temperature -2 C. Southwest wind 30-50 km/hr. Freezing level 1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Minimize exposure during periods of heavy loading from new snow, wind or rain.
- Be alert to conditions that change with aspect and elevation.
- Carefully monitor the bond between the new snow and old surface.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Problems
Loose Wet
Watch for rising freezing levels or rain-on-snow turning surface snow moist and saturating the snowpack. In the case of wet avalanches, the first 24 hours of rain-on-snow are the most hazardous as large, destructive avalanches are most likely to occur.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Where dry snow persists, the new snow has a weak bond to the interface below. Be especially cautious transitioning into wind-loaded terrain, more reactive deposits lurk in leeward features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A crust with weak, facetted snow above and below is buried by roughly 50-150 cm of snow. This layer is unlikely to be human-triggered, this current rapid and heavy load of new snow will stress the snowpack and may provide more insight into the dormancy of this deeper instability.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 25th, 2022 4:00PM
