Avalanche Forecast

Archived

Dec 4th, 2023–Dec 7th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Waterton Lakes, Waterton.

Travel is still very challenging due to low snow cover at low elevations. Big changes to the snowpack in the next three days with an incoming atmospheric river. Check updated weather forecasts regularly and choose conservative terrain.

Confidence

Low

Avalanche Summary

One size 1 windslab on a SE aspect on Mt Rowe. Nearby ski resorts reported skier accidentals to size 1.5 with new windslabs failing on facets.

Snowpack Summary

As of Dec 4, 10-30 cm storm snow with S-X SW winds have formed windslabs up to 50 cm deep. This overlies an weak early season snowpack made up of old windlsabs and facets. Basal crusts can be found in some areas above 1800m. Below Treeline is only at threshold in lee areas near the divide.

Incoming atmospheric river will likely have a dramatic effect on the snowpack, and lower elevations may be flushed out completely.

Weather Summary

Tues

Rain up to 10mm during the day with strong to extreme SW winds. Freezing levels will be above ridgetop with an alpine high of +4

Wed

Rain continues with strong to extreme ridgetop winds. Freezing levels remain at ridgetop but forecast to drop into the evening

Thurs

Snow through the day 10-25cm possible. Winds decreasing through the day to moderate SW.

For more weather info see the Mountain Weather Forecast.

Problems

Wet Slabs

Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.