Avalanche Forecast
Issued: Apr 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
wlewis,
Avalanche Canada
Areas that receive greater than 30 cm of snow by 10 am should consider hazard HIGH. Snowfall is expected to continue.
Minimize exposure to avalanche terrain, especially during heavy snowfall and wind. Conservative decision-making is key as snowfall amounts accumulate.
Summary
Confidence
Avalanche Summary
Warmer temperatures and some sun effect on Thursday produced wet loose avalanches. Wind slabs were last reported earlier in the week, in north-facing terrain features.
In the White Pass area on Saturday, a rider triggered a cornice fall from a distance, which produced a size 3 persistent slab avalanche on a northeast aspect at 1750 m. The avalanche was 200 cm deep and was suspected of having failed on a layer of facets above a crust buried in January.
Observations are also limited at this point in the season, please post any information or photos you have on the Mountain Information Network to help guide our forecasts.
Snowpack Summary
By 4 pm on Sunday, 20-40 cm of new snow may have fallen over another 20 cm of settling snow. Strong southerly winds will redistribute this storm snow into deeper deposits over previously wind-affected snow on north and east-facing slopes. South-facing terrain remains stripped back to a crust by these winds
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 in the White Pass region and remains a concern in terrain where the snowpack is thin. The lower snowpack consists of basal facets, particularly in shallow areas.
Weather Summary
Saturday Night
Mostly cloudy with 10-20 cm of snow with strong southerly winds. Freezing levels drop to valley bottom.
Sunday
Cloudy with another 15-30 cm possible and strong southerly winds. Freezing levels around 1000 m.
Monday
A mix of sun and cloud with moderate southwest winds. Freezing levels remain low around 500 m. Flurries are possible in isolated areas.
Tuesday
Mostly sunny with light southwest winds. Freezing levels around 500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Be careful to keep storm day fever from luring you out into bigger terrain features.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
Problems
Storm Slabs
Fresh and reactive storm slabs will build as snowfall continues overnight and into Sunday. Reactivity will be greatest in wind affected features. Avoid steep open slopes and wind loaded features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
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 9th, 2023 4:00PM
