Avalanche Forecast
Issued: Dec 12th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
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Avalanche Canada
Localized accumulations of 20 cm of new snow is possible on Friday. Dial back your terrain choices if you notice heavy loading from new snow and wind.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
THURSDAY NIGHT: 5-15 cm of new snow with the greatest accumulations in the Flathead area, 40 km/h wind from the west, alpine temperatures drop to -7 C.
FRIDAY: Scattered flurries with 5-10 cm of new snow, 30 km/h wind from the west, alpine high temperatures around -4 C.
SATURDAY: Mostly cloudy, light wind from the northwest, alpine high temperatures around -6 C.
SUNDAY: Mix of sun and cloud, light wind from the northwest, alpine high temperatures around -8 C.Â
Avalanche Summary
Recent avalanche activity is limited to small wind slab avalanches (size 1) triggered with explosives. Avalanche activity has quiet down since last weekend, when numerous large persistent slab avalanches (size 2-3) were reported at treeline and alpine elevations. Many of these avalanches ran on the November and October crust layers 40-100 cm deep. Triggering an avalanche on one of these deeper layers is still a possibility in steep rocky terrain.
Snowpack Summary
New snow and wind has formed fresh wind slabs at upper elevations. In sheltered areas 30-40 cm of snow from last weekend is gradually settling. Crust layers from November and October can be found 40-100 cm below the surface. These layers produced large avalanches with explosive triggers last weekend, but since then have appeared to gain strength. Large avalanches on these layers may still be possible to trigger in steep rocky terrain. Snowpack depths range between 50-100 cm at higher elevations and taper rapidly below treeline.
Problems
Wind Slabs
Triggering wind slab avalanches is likely at higher elevations where the wind has blown fresh snow into reactive slabs.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The likelihood of triggering a large avalanche on one of the crusts and weak layers in the lower snowpack is gradually reducing, but the consequence is high.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2019 4:00PM
