Avalanche Forecast
Issued: Jan 25th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cmortenson,
Avalanche Canada
Increasing southeasterly winds may begin to transport recent 5-15 cm of low density snow. Assess for fresh wind slabs along windy ridge crests or alpine areas. Remember, fresh wind slabs can be quite reactive, especially if they rest on top of buried surface hoar.
Summary
Confidence
Weather Forecast
Continued cool temps, increasing wind and a mix of clouds, sun and isolated flurries for early in the week.
MONDAY NIGHT: Mostly cloudy with clear periods, light to moderate southeast wind, treeline temperatures near -11C.
TUESDAY: Mix of sun and cloud with isolated flurries, light to moderate southeast wind, treeline temperatures around -13 C.
WEDNESDAY: Mix of sun and cloud with isolated flurries, moderate to strong easterly wind, treeline temperatures around -15 C.
THURSDAY: Sunny with cloudy periods, light southeast wind, treeline temperatures around -17 C.
Avalanche Summary
Isolated large avalanches failed during the weekend storm on recently buried surface hoar in the southwest of the region where recent snowfall amounts were on the higher end (up to 15 cm). A few cornice failures were observed late last week.
Otherwise, no significant avalanche activity has been reported since Tuesday, when there was a cycle of natural wind slab avalanches. Sporadic deep persistent slab avalanches were reported 1-2 weeks ago (triggered with heavy loads such as explosives and cornices), but deeper weak layers appear unreactive under the current conditions.
Snowpack Summary
5-15cm cm recent snow has buried surface hoar, which was reported as widespread below treeline and isolated at sheltered treeline and alpine locations. Buried sun crust can be found on steep solar. Widespread wind scoured surfaces, older wind slabs in alpine and exposed treeline locations and wind effect extending below treeline in open areas persist. Large cornices may becoming weak with cold temperatures.A thick crust exists near the surface below 1000 m. The middle snowpack is overall well settled. An older isolated surface hoar layer from early January, where preserved, is 20-60 cm deep.
The lower snowpack has two decomposing crust layers that have been causing a deep persistent slab problem for most of the past month. The upper crust is 70-140 cm deep in the Smithers area and continues to show occasional hard sudden results in snow pits. The deeper crust at the bottom of the snowpack continues to be a problem in shallow ranges like the Babines. These layers should be unreactive under the current conditions, but shallow rocky slopes should still be carefully assessed and approached with caution.
Terrain and Travel
- Make observations and assess conditions continually as you travel.
- Wind slabs are most reactive during their formation.
- Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.
- Caution around slopes that are exposed to cornices overhead.
Problems
Wind Slabs
Assess all slopes for wind slabs as wind shift from southerly to easterly. Reactive wind slabs may be found in the lee of windy exposed ridge crests and on steep alpine slopes. Cornice failures from above may trigger an otherwise stubborn wind slab in addition to being a hazard outright.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 26th, 2021 4:00PM
