Avalanche Forecast

Issued: Jan 2nd, 2018 5:52PM

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

ghelgeson, Avalanche Canada

Sea To Sky.

Continued warm temperatures should allow the snowpack to further settle and stabilize, but small storm slabs in more extreme terrain may still be an issue. Watch for the odd loose wet avalanche on steep solar aspects in the afternoon too.

Summary

Confidence

High - Timing, track, or intensity of incoming weather system is uncertain on Friday

Weather Forecast

Temperatures along the coast have moderated and this trend is expected to linger into Wednesday as a southwesterly flow of mild Pacific air continues. Those hoping for fresh snow will have to wait until late in the week.WEDNESDAY: Clear skies, light temperature inversion with the freezing level around 2500 m, very light southeast wind, no snow expected.THURSDAY: Overcast, light temperature inversion with the freezing level around 2500 m, light south/southwest wind, 1 to 3 mm of precipitation possible.FRIDAY: Overcast, freezing level around 2000 m, light to moderate south/southwest wind, 3 to 7 mm of precipitation possible.

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. On Sunday there was one report of a size 2.5 natural avalanche on a steep east facing feature in the alpine. There was also a small skier triggered avalanche on a southeast facing moraine feature at 1800 m. Loose dry avalanches to size 1 were reported from a variety of aspects.

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. The new snow rests on a variety of old surfaces including crust on solar aspects, old wind slabs, facets and isolated surface hoar below treeline, but avalanche activity on this interface continues to decrease as time and warm temperatures allow the old storm snow to settle and gain cohesion. 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

Aided by wind, time and warmth, the storm snow is settling into a stubborn old slab. For the most part, this slab is bonding well to the underlying surface, but continued warm temperatures could change its behavior.

Storm slabs could become more sensitive to human triggering as warm alpine temps linger.Caution with wind slabs, especially in steep, unsupported and/or convex terrain features.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

Natural loose wet avalanches remain possible Wednesday, especially on steep sun exposed slopes. With all the new snow in the last week, loose wet avalanches could entrain considerable mass, especially in terrain traps like gulleys.

Avoid sun exposed slopes especially if the snow is moist or wet.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Minimize exposure to solar aspects overhead, loose avalanches could travel surprisingly far.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 3rd, 2018 2:00PM