Avalanche Forecast
Issued: Mar 10th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
mconlan,
Avalanche Canada
The next storm rolls in on Thursday. Wind slabs are the primary concern for Thursday before storm slabs build.
Summary
Confidence
High -
Weather Forecast
WEDNESDAY NIGHT: Increasing clouds, 20 to 40 km/h west wind, alpine temperature -7 C.
THURSDAY: Cloudy with snowfall, accumulation 5 cm, 40 km/h southwest wind, alpine temperature -6 C.
FRIDAY: Cloudy with snowfall, accumulation 30 to 50 cm, 60 km/h southwest wind, alpine temperature -3 C, freezing level rising to 1000 m.
SATURDAY: Cloudy with snowfall, accumulation 60 cm, 30 km/h south wind, alpine temperature -2 C, freezing level 1100 m.
Avalanche Summary
No new avalanche observations were observed on Wednesday at the time of writing. Some avalanche activity was observed on southerly aspects on Tuesday during the heat of the day. A few cornices were also triggered, which did not trigger slabs on the slopes below.
Looking ahead, newly formed wind slabs will be the primary concern on Thursday. An avalanche cycle is expected to occur in the coming days if the forecast snow amounts hold true.
Snowpack Summary
An incoming storm will bring strong southwest wind and a bit of new snow on Thursday, forming wind slabs at treeline and alpine elevations. The new snow may overly feathery surface hoar on northerly aspects and in sheltered terrain features around treeline or a melt-freeze crust on southerly aspects and below treeline.
Around 100 to 200 cm overlies a persistent weak layers buried in mid-February that may still be a concern in parts of the region. The layer consists of feathery surface hoar crystals in areas sheltered from the wind and sugary faceted grains that formed during February's cold snap. Avalanche activity on this layer has mostly occurred west of Terrace along Highway 16 in the past week, but the layer could still be of concern anywhere it exists.
There are currently no layers of concern in the mid and lower snowpack.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
As a storm starts impacting the region on Thursday, new snow and strong wind will likely form new wind slabs. The most likely place to find them will be in steep terrain features adjacent to ridges. Look for signs of instability and be cautious if you enter steep features.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Around 100 to 200 cm of snow may overly a persistent weak layer buried in mid-February. The likelihood of triggering the layer may increase in the coming days as the forecast storm rapidly loads it.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 11th, 2021 4:00PM
