Avalanche Forecast
Issued: Apr 19th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
mconlan,
Avalanche Canada
The recent storm snow may take more time to bond to the snowpack, particularly where it rests on weak or smooth layers.
Summary
Confidence
Moderate
Avalanche Summary
Small to large (size 1 to 2) storm slab avalanches were triggered by riders, explosives, and naturally between Sunday and Tuesday, generally being about 30 cm thick and primarily at alpine and treeline elevations. Some of them were triggered by small pieces of cornices failing.
Human triggering of avalanches is likely decreasing as the storm snow settles, but the possibility remains of triggering slabs in steep lee terrain features or where the storm snow isn't bonding to surface hoar crystals or a smooth crust. Brief periods of sunny skies could also trigger small loose wet avalanches out of steep, rocky terrain on sun-exposed slopes.
Snowpack Summary
Around 50 cm of snow accumulated since the weekend, forming storm slabs. The wind was strong from the south to southeast at times, likely forming wind slabs in lee terrain features on northerly slopes. The surface snow on sun-exposed slopes may moisten during periods of sunny skies.
All this snow may sit on a weak layer of surface hoar crystals on sheltered and shaded treeline and alpine slopes or a hard melt-freeze crust on sun-exposed slopes and on all aspects below 1500 m.
The remainder of the snowpack is well-bonded.
Cornices are large and looming at this time of year.
Weather Summary
Wednesday Night
Mostly clear skies with no precipitation, 20 km/h south wind, treeline temperature -8 °C.
Thursday
Cloudy with snowfall, accumulation 2 to 5 cm, 30 to 50 km/h southeast wind, treeline temperature -7 °C, freezing level 1000 m.
FridayCloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h south wind, treeline temperature -5 °C, freezing level 1400 m.
SaturdayCloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h south wind, treeline temperature -2 °C, freezing level 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully monitor the bond between the new snow and old surface.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Even brief periods of direct sun could produce natural avalanches.
Problems
Storm Slabs
Storm slabs have been reactive to human traffic since the weekend. The slabs may take extra time to bond to the snowpack, particularly where they sit on surface hoar crystals or a smooth crust. Best to give the snow time to settle before entering consequential terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 20th, 2023 4:00PM
