Avalanche Forecast
Issued: Nov 23rd, 2019 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
cgarritty,
Avalanche Canada
Venture cautiously as you investigate the outcome of the storm. Very dangerous conditions are likely in areas that saw more snow than rain. Use this forecast as an initial assessment and gather information as you travel.
Post your observations to the Mountain Information Network!
Summary
Confidence
Weather Forecast
Saturday night: Cloudy with continuing flurries bringing approximately 10 cm of new snow. Strong northwest winds. Freezing level descending to 1000 metres.
Sunday: A mix of sun and cloud. New snow totals at treeline of 10-15cm with up to a metre or more in higher alpine locations. Moderate to strong northwest winds. Alpine high temperatures around -5 with freezing levels to 900 metres.
Monday: A mix of sun and cloud with isolated flurries and a trace of new snow. Light to moderate southwest winds. Alpine high temperatures around -7 with freezing levels to 500 metres.
Tuesday: A mix of sun and cloud, clearing over the day. Light to moderate northeast winds. Alpine high temperatures around -8.
Avalanche Summary
Observations from the succession of storms impacting the region have yet to come in, but it is expected that the significant load of new snow (along with strong winds) has been promoting widespread natural storm slab avalanches at elevations where snow has accumulated instead of rain.
Looking forward, clearing weather is likely to make travel in the mountains a more inviting prospect, however this is a time to be on high alert in any areas where new snow buried a smooth surface. Concern is reduced in areas where the new snow hasn't yet overcome the depth of ground roughness.
Snowpack Summary
Heavy rain over Friday and Saturday is expected to have eroded much of the patchy snow cover that existed below the alpine while potentially adding up to a metre or more of new snow to alpine areas - potentially tripling recently observed snowpack depths at higher elevations. Beyond the sheer quantity of new load, the bond between the new snow and the melt-freeze crust on the previous surface is expected to be poor, particularly in areas that did not experience rain in advance of the recent snowfall (higher elevations).
Problems
Storm Slabs
Heavy snowfall has likely formed thick and reactive storm slabs in the alpine. A poor bond is expected between the new snow and the old snow surface. Picking out where the new snow sits on a smooth surface and where it is anchored in place by ground roughness may be tricky on Sunday.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 24th, 2019 5:00PM
