Avalanche Forecast
Issued: Feb 11th, 2021 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jcoulter,
Avalanche Canada
Wind and extreme cold is not a fun combo! Be mindful of wind loaded features and use a conservative mindset when planning objectives in these temperatures.
Summary
Confidence
Moderate -
Weather Forecast
THURSDAY NIGHT - Still cold, but still sunny / strong to extreme south east / low of -24
FRIDAY - A mix of sun and cloud / strong to extreme south east wind / alpine high temperature near -15
SATURDAY - Cloudy, strong south east wind / alpine high -13
SUNDAY - Cloudy, flurries, light to moderate southerly wind / -15
Avalanche Summary
A size 2 natural windslab was reported near the ski area. Wind slabs have also been reactive to human triggering in wind loaded and cross loaded features. Most ski cut results have been in the size 1 to 1.5 range, but bigger terrain features could produce larger propagation and bigger avalanches!Â
Check out this forecaster MIN post from Microwave from Thursday to see the widespread wind effects.Â
A Feb 9th MIN observation shows some stiff wind affected snow over sugary facets.
Evidence of recent natural wind slab avalanches (likely occurring Saturday) were observed on Sunday as discussed in this MIN report. Small loose dry avalanches were also reported, in some cases likely triggered by the sun.
Snowpack Summary
Hard slabs, scoured slopes and sastrugi will be present where outflow effects have been the strongest. In more sheltered zones, reactive wind slabs will be found on a variety of aspects and elevations due to terrain effects and the variable wind directions.
In more sheltered areas, the cold temperatures are encouraging surface faceting. The late January interface is down 30-50 cm, consisting of isolated surface hoar in sheltered locations, and previous wind effect in exposed areas. On solar aspects, a buried sun crust can be found below 1000 m.Â
The lower snowpack has two decomposing crust layers. The upper crust is 70-140 cm deep and continues to show occasional hard, sudden results in snow pits. The deeper crust at the bottom of the snowpack is more prevalent in shallow snowpack ranges. These deep persistent layers seem to be dormant under the current conditions, but shallow rocky slopes should still be carefully assessed and approached with caution.Â
Terrain and Travel
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Variable wind may form reactive slabs on multiple aspects, and outflow winds continue to impact loose snow and reverse load features. Avalanches will be most likely in wind loaded areas and where the snow feels stiff or punchy. Note that in some places avalanche hazard may be elevated where winds have penetrated into unexpected places even at lower elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 12th, 2021 4:00PM
