Avalanche Forecast
Issued: Apr 9th, 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.
ahanna,
Avalanche Canada
Continue to make conservative terrain choices as the snowpack adjusts to the significant new snow load.
Summary
Confidence
Moderate
Avalanche Summary
On Saturday, natural and controlled storm slabs and loose wet avalanches were reported, size 1-2 in the south of the region.
On Friday numerous persistent slab avalanches to size 2.5 were reported near Stewart. Avalanches were triggered both naturally and by riders (some remotely) and on a variety of aspects and elevations, running on a weak layer buried March 31st.
Snowpack Summary
30-60 cm of recent snow fell dry above 1500 m and as rain below 700 m. At upper elevation, the new snow continues to be redistributed by southwest winds into wind slabs on north-to-east-facing slopes. The recent snow sits over wind-affected surfaces, weak faceted crystals or a crust on south-facing slopes.
A weak layer buried at the end of March sits 50-80 cm deep in most areas (potentially over 1m deep in immediate coastal terrain). It includes facets and surface hoar in shaded areas, and a melt-freeze crust elsewhere. This layer has shown limited reactivity within the past week.
The mid and lower snowpack are considered generally strong and well-bonded. In far northern reaches of the region, basal facets may exist which are currently considered inactive. This layer may become active with abrupt changes to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged warming.
Weather Summary
Sunday night
10-15 cm of new snow. Strong southwest wind. Alpine low -7. Freezing levels around 800 m.
Monday
Around 5 cm of new snow. Moderate southwest winds. Alpine high -2 C. Freezing levels around 1000 m.
Tuesday
A mix of sun and cloud. Light northwest wind. Alpine high -2 C. Freezing levels around 1000 m.
Wednesday
Cloudy. Moderate southwest winds. Alpine high -5 C. Freezing levels around 800 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Stick to simple terrain features and be certain your location isn't threatened by overhead hazard.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Avoid freshly wind loaded terrain features.
Problems
Storm Slabs
Fresh storm slabs will likely remain reactive on Monday. Coastal areas have seen much heavier snowfall. Expect greater reactivity and size of possible avalanches as you travel further west.
At lower elevations, the saturated snowpack may be prone to rider-triggered loose wet avalanches. Avoid slopes with punchy, wet snow.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Buried layers from late March reached a tipping point and became very reactive on Friday, with impressive propagation. Of primary concern is a layer of facets and surface hoar buried 50-80 cm on shaded slopes. On other slopes, this layer is a crust with facets above. Avoid steep open slopes capable of producing large avalanches, storm snow is adding a significant load to the snowpack.
Reactivity has been most concerning west of Stewart, however, this layer extends throughout the Northwest Coast region.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 10th, 2023 4:00PM
