Avalanche Forecast

Issued: Nov 27th, 2019 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada shorton, Avalanche Canada

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Wind slab avalanches remain the primary concern as the Lizard Range is missing out on the storm hitting Alberta.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

WEDNESDAY NIGHT: Some isolated flurries continue near the Alberta border with 5-10 cm, no snow expected in the Lizard Range, 60 km/h wind from the east, alpine temperatures drop to -18 C.

THURSDAY: Clearing skies throughout the day with some isolated flurries bringing trace amounts of snow, 30 km/h wind from the east, alpine high temperatures around -15 C.

FRIDAY: Mostly sunny, light wind from the northeast, alpine high temperatures around -12 C.

SATURDAY: Mostly sunny, light wind, alpine high temperatures around -10 C.

Avalanche Summary

Eastern parts of the region near the Alberta border may have received enough new snow to develop fresh and potentially thick wind slabs, while old wind slabs remain the main concern in western parts of the region such as the Lizard Range and Harvey Pass. Concern is reduced in areas where the snow depths have not yet reach the threshold for avalanches. The last reported avalanches were several small wind slabs last weekend (including this MIN report from Harvey Pass).

Snowpack Summary

The Lizard Flathead region unfortunately missed out on the bulk of the storm that hit Alberta. Little to no snow fell in the Lizard Range while parts of the region near the divide (e.g. south of Sparwood) may have received 10-15 cm of snow over the past few days. The snowpack is still thin with many rocks and trees sticking out. The snowline starts around 1500 m, with about 40 cm of snow around 1700 m, and 50 to 100 cm of snow in the alpine. Two crusts have been reported in the middle of the snowpack. There is uncertainty about how the snow is bonding to these crusts, and they may act as a sliding layer for snow above them. Be prepared to back off to mellow terrain if you encounter signs of instability such as whumpfs or shooting cracks, which could indicate these layers are capable of producing avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for hard wind slabs in alpine terrain and near ridgetops. Eastern parts of the region near Alberta may have thicker and more reactive wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 28th, 2019 4:00PM