Avalanche Forecast
Issued: Jan 5th, 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.
shorton,
Avalanche Canada
Navigate around wind loaded slopes and keep in mind the potential for surprisingly large avalanches due to isolated weak layers.
Summary
Confidence
Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.
Weather Forecast
The windy storm continues until Wednesday afternoon.
TUESDAY NIGHT: Scattered flurries with localized accumulations of 5-10 cm, strong southwest wind, temperatures around -4 C.
WEDNESDAY: Flurries continue with another 5-10 cm of snow throughout the day, moderate to strong southwest wind, temperatures around -6 C.
THURSDAY: Partly cloudy, strong south wind, temperatures around -4 C.
FRIDAY: Partly cloudy, moderate south wind, temperatures around -6 C.
Avalanche Summary
Over the weekend there were several reports of natural size 1-2 slab avalanches in east-facing alpine terrain (see some photos here, here, and here). Most of the activity was on wind loaded slopes. Some large whumpfs were reported in the Babines. No persistent or deep persistent slab avalanches have been reported since Dec 22, however there is still potential to trigger large avalanches in steep rocky terrain.
Snowpack Summary
Strong to extreme wind is moving around 30-50 cm of snow that has fallen since New Year's Day. Thick wind slabs can be found in exposed open terrain, sheltered terrain should have mostly low density snow. However, isolated storm slabs could be forming on steep rolls in sheltered areas where recent snow may be settling above surface hoar.
The lower snowpack has two crusts with potentially weak snow around them. One is 60-90 cm below the surface and the other is near the ground. These layers produced avalanches on Dec 21 and 22, but since then have been trending towards dormancy. We are uncertain about how likely it is to trigger avalanches on these deeper layers, but would be most suspect of shallow rocky slopes in the alpine.
Terrain and Travel
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Choose slopes that are well supported and have limited consequence.
- Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.
Problems
Wind Slabs
Intense wind from the southwest has left touchy slabs in leeward terrain. In some isolated sheltered areas recent snow may be settling above surface hoar.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Triggering large avalanches on weaknesses in the lower snowpack remains a possibility. In some areas the concern is weak snow around crusts 60 to 90 cm deep, while in others it is weak snow near the bottom of the snowpack. This problem is best managed by avoiding steep rocky slopes and approaching challenging and complex avalanche terrain with extra caution.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 6th, 2021 4:00PM
