Avalanche Forecast
Issued: Apr 24th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Loose Wet.
mconlan,
Avalanche Canada
Wintry conditions are found in the alpine, whereas more spring-like problems are prominent at lower elevations. Travel cautiously, particularly during the heat of the day when avalanche activity is most likely.
Summary
Confidence
Avalanche Summary
Many small to large (size 1 to 2) wet loose avalanches were observed over the weekend and on Monday, generally occurring out of steep alpine terrain between 1800 m and 2100 m. Small cornice chunks were also triggered naturally and by riders on Monday. One of the chunks triggered a a small (size 1) slab on a north aspect at 2100 m.
We expect to see similar avalanches in the coming days at all elevations during periods of sunny skies and an increasing freezing level. The likelihood of seeing very large avalanches releasing on the buried weak layer described in the Snowpack Summary will increase with each day of warming this week.
Snowpack Summary
Moist snow is found on all aspects up to 1800 m, which will freeze into a melt-freeze crust overnight. Dry snow may be found above 1800 m on northerly aspects, where wind slabs may linger in steep leeward slopes from southerly wind.
The middle of the snowpack is consolidated with various layers of moist snow, hard snow, and melt-freeze crusts.
A layer of weak faceted grains may be found near the base of the snowpack at treeline and alpine elevations. The likelihood of this layer being triggered will increase with each day of warming for the coming weeks. Humans are most likely to trigger it in steep and rocky slopes where the snowpack is relatively thin.
Cornices are large and looming at this time of year and will weaken with daytime warming.
Weather Summary
Monday Night
Mostly cloudy with no precipitation, 20 to 30 km/h southwest wind, treeline temperature -4 °C, freezing level 1300 m.
Tuesday
Mostly sunny skies with no precipitation, 10 to 30 km/h west wind, treeline temperature -1 °C, freezing level rising to 1900 m.
WednesdayCloudy with light snow or rain, accumulation 2 to 5 cm above 2500 m, 30 to 60 km/h southwest wind, treeline temperature 3 °C, freezing level 2500 m.
ThursdayMostly sunny with no precipitation, 10 to 20 km/h variable wind, treeline temperature 6 °C, freezing level 3500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully evaluate steep lines for wind slabs.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
Problems
Wind Slabs
Wind slabs may be found in steep leeward slopes at treeline and alpine elevations from recent southerly wind. Assess for slabs prior to committing to any terrain with a potential high consequence.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large at this time of year and will become more prone to fail as they warm up with spring weather. Stay well back from them when travelling on ridgelines and limit your exposure when travelling on slopes below them.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Wet loose avalanche activity is expected to continue during periods of strong sun and with daytime warming. Limit your exposure to steep terrain on sun-exposed slopes during periods of strong sun and anywhere the snow starts feeling sloppy.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 25th, 2023 4:00PM
