Avalanche Forecast
Issued: Apr 10th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
mconlan,
Avalanche Canada
Touchy wind slabs could be triggered by riders. Seek the most sheltered terrain you can find for the best riding conditions.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations. Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
SATURDAY NIGHT: Partly cloudy, 20 km/h west wind, alpine temperature -12 C.
SUNDAY: Partly cloudy with isolated flurries, 20 km/h northwest wind, alpine temperature -13 C.
MONDAY: Cloudy with snowfall, accumulation 2 to 5 cm, 50 km/h south wind, alpine temperature -7 C.
TUESDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 50 km/h south wind, alpine temperature -5 C, freezing level rising to 1000 m.
Avalanche Summary
On Friday, the field team observed natural wind slabs from a steep, alpine south facing gulley features around White Pass. They were also able to remotely triggered multiple size 1 to 2 wind slabs, with the furthest avalanche releasing 350m away! The reactive wind slabs ran on a 2 cm thick melt-freeze crust down 30 to 70 cm.
Snowpack Summary
Around 15 cm of recent snow has been redistributed by strong northeast wind into hard and touchy wind slabs everywhere except for the most sheltered terrain features. The snow overlies a hard melt-freeze crust on sun-exposed slopes that exists up to 1200 m. Wind slabs 30 to 70 cm thick have been found above this crust and they have been reactive to riders and snowpack tests (see here).
The White Pass area has a deep snowpack without any deeper layers of concern. The Tutshi Lake / Paddy Peak area should be assessed on a slope by slope basis, as some lingering snowpack weaknesses may still exist on isolated slopes. The Wheaton's shallower snowpack is dominated by hard wind slabs overlying sugary facets and depth hoar. It's an untrustworthy snowpack structure that requires conservative terrain selection and diligent travel habits.Â
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
There is widespread wind effect from strong wind, which produced touchy wind slabs that could still be triggered by riders. Use caution in steep, wind-affected terrain and look for signs of instability prior to committing yourself. Wind slabs may be particularly touchy on sun-exposed slopes, where they overly a hard melt-freeze crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 12th, 2021 4:00PM
