Avalanche Forecast

Issued: Jan 3rd, 2018 4:51PM

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

Avalanche Canada ghelgeson, Avalanche Canada

Low avalanche danger doesn't necessarily equate to no avalanche danger. The odd small storm slab may still be human triggerable in more extreme terrain. The picture should start to change on Saturday as storm snow returns to the Sea to Sky.

Summary

Confidence

Moderate - Freezing levels are uncertain on Friday

Weather Forecast

The weather pattern is changing, albeit slowly.  As the ridge shifts east, a trough pattern on the west coast begins to bring cloud and precipitation beginning Thursday.THURSDAY: Overcast, light temperature inversion with the freezing level around 2500 m, light southerly wind, trace of precipitation possible in the late afternoon.FRIDAY: Overcast, freezing level around 2000 m, light to moderate south/southwest wind, 3 to 6 mm of precipitation expected.SATURDAY: Overcast, freezing level around 1100 m, light to moderate southwest wind, 3 to 6 mm of precipitation expected.

Avalanche Summary

On Tuesday snow balling and pin wheeling was reported from north facing aspects. On Monday several loose wet avalanches to size 1 were reported from southeast and south facing features between 1800 and 2100 m.

Snowpack Summary

On Sunday a slight crust began to form on south and southwest facing aspects as warm temperatures and sun combined to moisten the snow surface. By Tuesday the upper 5 cm of the snowpack had started to become moist, even on upper elevation northeast facing features. Last Thursday and Friday two successive storms produced 50 to 70 cm of snow with wind mainly out of the south. Time and warm temperatures have allowed this snow to settle and bond well with the underlying surface. The exception may be below treeline where there may be isolated pockets of buried surface hoar. Wind effect in the alpine has been extensive but reported wind slab avalanche activity has ceased.40 to 100 cm below the surface there is a widespread melt-freeze crust that was buried on December 15th. This layer has not produced much in the way of avalanche activity and is likely trending towards dormancy. Beneath the mid-December crust, the lower snowpack is generally strong and well settled.

Problems

Storm Slabs

An icon showing Storm Slabs
Aided by wind, time and warmth, the storm snow has settled into a stubborn old slab. For the most part, this slab is bonding well to the underlying surface but there may still be an issue in more extreme terrain.
Caution with wind slabs, especially in steep, unsupported and/or convex terrain features.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Jan 4th, 2018 2:00PM