Avalanche Forecast
Issued: Nov 22nd, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
astclair,
Avalanche Canada
New slab development begins with incoming snow and wind. Watch for changing conditions, especially in windy areas where 15 cm of snow could accumulate by the end of the day. Deeper layers remain a concern.
Summary
Confidence
Low - Uncertainty is due to the timing of the incoming weather system. Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.
Weather Forecast
Friday night: Increasing clouds, freezing level around 1200 m, light southwesterly winds, and a trace of precipitation.
Saturday: Overcast, freezing level around 1200 m, moderate southwesterly winds, and 5-15 cm of snow.
Saturday night: Another 5-15 cm of snow possible with southwesterly winds. Higher precipitation amounts will fall in the northern part of the region.
Sunday: Continuing flurries, winds shifting to the west/northwest, and the freezing level dropping from 1200 m.
Avalanche Summary
The last reports of avalanches came in on Tuesday, November 19th.Â
Snowpack Summary
The incoming storm brings a change and a test for our snowpack. After a week of clear skies, the existing snow surfaces may not bond well with the new snow. As the new snow accumulates, it could develop into a reactive slab, especially in drifted areas near and above tree line.Â
The incoming storm presents an opportunity to observe how the problem weak layers (late October crusts) buried 40-70 cm deep in the snowpack react to a new load.Â
The average snowpack depth at tree line is approximately 100 cm.
Problems
Storm Slabs
The combination of new snow and wind may form reactive storm slabs throughout the day, particularly in drifted areas near and above tree line.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The incoming storm could lead to avalanches breaking down to crusts from late October buried 40 to 70 cm deep.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 23rd, 2019 5:00PM
