Avalanche Forecast
Issued: Feb 6th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
cgarritty,
Avalanche Canada
Investigate new snow amounts and reactivity in an initial assessment travel mode on Tuesday. Raise your guard as you approach exposed terrain where overlapping wind slabs and persistent slabs demand thoughtful terrain selection.
Summary
Confidence
Moderate
Avalanche Summary
We don't yet have observations from Monday's storm, however it's likely an uptick in natural storm and/or wind slabs occurred as moderate snowfall and high winds took over the region.
A MIN report from Sunday gives an indication of wind slab hazards that existed in the region in advance of our most recent snow and wind. Slabs that are a step larger will need to be managed on Tuesday, in addition to the uncertain effects of the increased load on our buried persistent weak layers.
On Friday a natural avalanche cycle up to size 3 took place in the south west corner of the forecast region. These avalanches failed on the late January crust.
If you are out in the backcountry please consider filling out a Mountain Information Network report.
Snowpack Summary
Ongoing snowfall and southwest winds have accumulated around 50-60 cm of storm snow that is continuously being blown into wind slabs. This growing storm total sits on a crust from the warming event on January 25th and will need time to form a solid bond.
The mid and lower snowpack continues to bond and stabilize. A few concerning weak layers can still be found in the top meter of the snowpack including a surface hoar layer from early January and a crust from late December.
Weather Summary
Monday night
Clearing. Winds easing to light southwest.
Tuesday
Increasing cloud with flurries bringing up to 5 cm of new snow. Light southwest winds. Treeline high temperatures around -8.
Wednesday
A mix of sun and cloud with isolated flurries. Light to moderate southwest winds shifting southeast and increasing. Treeline high temperatures around -10.
Thursday
Cloudy with continuing flurries bringing 5-10 cm of new snow, including overnight amounts. Strong south winds. Treeline high temperatures around -3.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs may be poorly bonded to the underlying crust.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Problems
Wind Slabs
Snowfall and southwest winds formed reactive wind slabs throughout the day on Monday. North through east aspects in exposed areas will be the most likely places to trigger one.
Aspects: North, North East, East, South East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A number of buried weak layers remain possible to trigger. These layers appear to be most problematic in upper treeline and alpine elevations, in shallow, variable, rocky start zones. A sensitive wind slab overlying this problem could serve as the perfect trigger for a destructive step-down avalanche.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 7th, 2023 4:00PM
