Avalanche Forecast
Issued: Feb 21st, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
mconlan,
Avalanche Canada
Expect to find wind slabs on atypical southerly slopes. Remember that any incident in cold weather can be serious.
Summary
Confidence
Moderate
Avalanche Summary
We haven't received reports yet from Tuesday but suspect that many storm slab and wind slab avalanches were triggered within the recent storm snow.
Looking forward, the cold weather may mean that newly formed wind slabs could remain human-triggerable for the coming days. These slabs are likely on atypical south to west aspects due to the northeast wind.
Snowpack Summary
Strong northeast wind is redistributing the 50 to 100 cm of recent storm snow into wind slabs on southerly slopes. Very cold weather may allow for these slabs to linger for longer than is typical. All this storm snow may overly a small layer of surface hoar crystals in terrain sheltered from the wind around treeline elevations.
The mid-pack is generally strong with remnants of old weak layers from January, which haven't produced recent avalanches.
Large and weak facets that formed in November are found near the base of the snowpack. Although the likelihood of triggering this layer is low at this time, the consequence of doing so would be high. This layer is most likely to be human-triggered in thin, rocky slopes at alpine and upper treeline elevations.
Weather Summary
Tuesday Night
Mostly clear skies with no precipitation, 30 km/h northeast wind, treeline temperature -25 °C.
Wednesday
Mostly clear skies with no precipitation, 20 km/h northeast wind, treeline temperature -26 °C.
ThursdayMix of sun and cloud with no precipitation, 20 km/h northeast wind, treeline temperature -26 °C.
FridayIncreasing clouds with no precipitation, 20 to 40 km/h west wind, treeline temperature - 20 °C.
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.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Wind Slabs
Northeast wind is forming wind slabs on south to west slopes at treeline and alpine elevations. Assess for slab development prior to committing to high-consequence terrain.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
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 and continues to produce sporadic, destructive avalanches. Human-triggering is most likely on steep, shallow, rocky slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 22nd, 2023 4:00PM
