Avalanche Forecast
Issued: Feb 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Forecast flurries and any loose snow still available for transport will be going for a ride on an extreme southwest wind on Thursday. Watch for blowing snow and expect rapid slab formation on leeward slopes if you see it happening. Winds this strong can form slabs surprisingly low in the terrain.
Summary
Confidence
Avalanche Summary
No new avalanches have been reported in the region.
Numerous natural wet loose releases were observed on Monday at treeline and below as rain saturated our recent storm snow. Alpine observations are still lacking, however with precipitation falling as snow, higher elevations likely experienced some degree of natural avalanche cycle during the most recent storm pulse.
Looking forward, the highest elevations of the island where dry snow has accumulated remain a concern for wind slab potential. Cooling temperatures should have by now locked the snowpack in place where precipitation has instead fallen as rain.
Snowpack Summary
15-20 cm of dry snow has so far been observed at treeline, with slightly enhanced amounts expected in the alpine in the wake of 20-50 mm of precipitation falling in the region from Monday through Tuesday, mostly as rain and heavily favouring the south and west of the island.
The new snow overlies moist snow above 1300 m and a new breakable crust below this elevation, both from rain preceding snowfall over the course of the storm. This rain saturated as much as 70 cm that accumulated above 700 m from the previous storm pulse at the end of last week.
These upper snowpack characteristics top a melt-freeze crust that is now likely breaking down where it was thinnest. The crust was previously up to 10 cm thick at lower elevations and tapered to 1 cm thick on shaded or high elevation terrain. A few cm of softer snow recently found immediately below this crust is almost certainly now settled and bonded along with the remainder of the snowpack beneath it.
Weather Summary
Wednesday night
Cloudy with flurries bringing 5-10 cm of new snow. Strong south winds.
Thursday
Cloudy with easing flurries from overnight bringing up to 5 cm of new snow before clearing to a mix of sun and cloud. Strong to extreme south winds. Treeline high temperatures around 0 with freezing levels rising to 1300 m.
Friday
Cloudy with flurries bringing 5-10 cm of new snow, light rain to a possible 1200 m. Strong south winds easing to light northeast. Treeline high temperatures around -1 with freezing levels to 1200 m.
Saturday
Cloudy with flurries bringing about 5 cm of new snow. Strong southwest winds. Treeline high temperatures around -2.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs are most reactive during their formation.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Make observations and assess conditions continually as you travel.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Wind Slabs
10-20 cm of new snow above 1500 m - likely more in higher alpine locations - formed wind slabs in leeward terrain features toward the end of the Monday-Tuesday storm. Strong to extreme forecast winds could move what snow is left for transport on Thursday to form reactive new wind slabs over more stubborn old ones
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 9th, 2023 4:00PM
