Avalanche Forecast
Issued: Feb 19th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Deep Persistent Slabs.
trettie,
Avalanche Canada
Carefully assess new snowfall amounts. size and sensitivity of storm slabs could vary throughout the region as a result of highly variable storm totals.
Summary
Confidence
Avalanche Summary
On Saturday one natural large cornice fall was observed. Explosive control produced a few very large deep persistent slab avalanches. These avalanches were in upper treeline and alpine terrain.
Snowpack Summary
Snowfall amounts vary greatly throughout the region, up to 80cm of recent storm snow could be found. The recent snow is settling into storm slabs that will be most reactive where either wind has stiffened the snow or they overlie a layer of recently buried surface hoar.
The mid-pack is showing signs of strengthening. A surface hoar layer down roughly 60 to 80 cm has not produced avalanches recently but can still be found in isolated terrain features specifically sheltered, treeline, and upper below treeline.
The lower snowpack is composed of large and weak facets from November located near the base of the snowpack. Additional load or step-down avalanches over the next few days may wake this layer up.
Weather Summary
Sunday Night
Cloudy with up to 10cm of new snow expected. Light to moderate northwest winds and a low of -9 at 1800m.
Monday
Mostly cloudy with up to 15cm of new snow in the afternoon. Light westerly winds and temperatures at 1800m around -7.
Tuesday
Mostly cloudy with the possibility of light flurries bringing up to 5cm of new snow. Moderate to strong northeast winds and temperatures at 1800m falling to -21.
Wednesday
Mostly sunny with no new snow expected. Moderate easterly winds and temperatures at 1800m around -22.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Minimize your exposure time below cornices.
Problems
Storm Slabs
Rider triggerable storm slabs could be found at all elevations and on all aspects. The largest and most reactive will likely be found at treeline and above on north and east aspects. Large cornices have formed as a result of the recent stormy weather.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2023 4:00PM
