Avalanche Forecast
Issued: Jan 27th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
Fresh storm slabs may become increasingly reactive throughout the day, especially in wind loaded areas. Watch for signs of instability such as whumfing, cracking, and recent avalanches.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
WEDNESDAY NIGHT - Flurries, 5-10 cm / moderate to strong south wind / alpine low temperature near -8Â
THURSDAY - Flurries, 5-10 cm / moderate to strong south wind / alpine high temperature near -5
FRIDAY - Mainly cloudy with isolated flurries / light southwest wind / alpine high temperature near -5Â
SATURDAY - Mainly cloudy with isolated flurries / moderate south wind / alpine high temperature near -7
Avalanche Summary
With continued snowfall through the day and strong winds expected, storm slabs could become increasingly reactive throughout the day on Thursday, especially in wind loaded areas.
A size 1 human triggered wind slab avalanche was reported on a northwest aspect at 2100 m near Whitewater on Sunday.Â
Another size 1 human triggered wind slab avalanche was reported on a northeast aspect at 2000 m in the Five Mile Provincial Park area on Saturday.Â
Snowpack Summary
10-20 cm of new snow is expected in the region between Wednesday night and Thursday afternoon, with moderate to strong south wind.Â
One or more crusts may exist in the upper snowpack depending on elevation and area within the region. The uppermost crust extends up to around 2000 m. In higher terrain, 15-20 cm of snow may sit over a crust and/or large surface hoar crystals.
Another layer of surface hoar found 20-50 cm below the surface in isolated areas in the north and east of the region appears to be gaining strength but could become more reactive with some new snow in the coming days.
A couple of crusts surrounded by weak faceted grains are buried deep within the snowpack. The upper layer is 80 to 130 cm deep and the lower is near the ground.Â
Terrain and Travel
- Watch for changing conditions today, storm slabs may become increasingly reactive.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Problems
Storm Slabs
Up to 20 cm could be expected by the end of the day, forming storm slabs that may increase in reactivity throughout the day.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Continued caution is warranted around steep, shaded slopes around treeline where pockets of buried surface hoar may still be preserved. This layer may become more reactive with the additional load from new snow and wind loading on Thursday.
Aspects: North, North East, North West.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: Jan 28th, 2021 4:00PM
