Avalanche Forecast
Issued: Apr 14th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
jsmith,
Avalanche Canada
Lingering wind slabs may remain reactive to human triggers on lee aspects in the alpine.
Avoid steep, rocky, and wind affected areas where triggering slabs are more likely.
Summary
Confidence
Moderate
Avalanche Summary
A size 3 persistent slab avalanche was reported on a southeast aspect in the alpine west of Kelsall lake on Thursday. It was suspected to have been triggered by solar radiation.
Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.
Snowpack Summary
20-30 cm of recent soft snow may have seen some redistribution by recent wind but above 1200 m, it remains largely available for wind transport. Below 1200 m, moist snow or a thin crust may exist at or near the surface.
The new snow sits over previously wind-affected snow on north and east facing slopes and a crust on south facing slopes.
A weak layer of surface hoar/crust/facets buried in early January is now buried over 1 m deep in most areas. This layer has produced recent avalanche activity and remains a concern in terrain where the snowpack is thin. The lower snowpack consists of basal facets, particularly in shallow areas.
Weather Summary
Friday Night
Mostly cloudy / 20 km/h east ridgetop wind / Temperature at treeline around -5 C / Freezing level valley bottom
Saturday
Mix of sun and cloud with isolated flurries; 0-10 cm, then another 3-15 cm overnight / 20 km/h southeast ridgetop wind / Temperature at treeline around -3 C / Freezing level 1100 m
Sunday
Mix of sun and cloud / 10 km/h east ridgetop wind / Temperature at treeline around -3 C / Freezing level 1100 m
Monday
Cloudy with isolated flurries; 0-3 cm / 10 km/h northwest ridgetop wind / Temperature at treeline around -4 C / Freezing level 800 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.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Cornice failure may trigger large avalanches.
- Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
Problems
Wind Slabs
Lingering wind slabs may remain reactive to human triggers on lee aspects in the alpine.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
A layer of facets sitting on a crust buried in January has recently been reactive. Triggering is most likely in areas where the snowpack is thin and weak, or with a heavy load like a cornice fall or the weight of a smaller avalanche in motion triggering this deeper layer.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 15th, 2023 4:00PM
