Avalanche Forecast

Issued: Jan 2nd, 2018 5:59PM

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.

Avalanche Canada ghelgeson, Avalanche Canada

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

Moderate - 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: A few clouds, light temperature inversion with the freezing level around 2500 m, very light southeast wind, no snow expected.THURSDAY: Overcast, light temperature inversion, cool air in the valley, warmer above freezing air between 1500 m and 2500 m, light south/southwest wind, trace of precipitation possible.FRIDAY: Overcast, freezing level around 800 m with the potential for a temperature inversion with a layer of warmer above freezing air between 1500 m and 2600 m, light south/southwest wind, trace of precipitation possible.

Avalanche Summary

On Monday reported avalanche activity was limited to small natural loose wet avalanches on southwest, south and southeast facing features between 1800 and 2300 m. On Sunday isolated soft slabs were reported from steep features, gully walls and convex rolls on south and southwest facing terrain to size 1. Isolated loose avalanches to size 1 from steep solar facing terrain were also reported. On Saturday a widespread avalanche cycle to size 1.5 was reported with avalanches failing within the recent storm snow.

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 80 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 widely reported but wind slab activity has slowed to a trickle.A widespread melt-freeze crust buried mid-December exits throughout the region. This crust is down around 30 to 60 cm in the Duffey. Around the Coquihalla it's about 100 cm below the surface. 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 is settling into a stubborn old slab. For the most part, this slab is bonding well to the underlying surface, but there is a chance that continued warm temperatures could change its behavior.
Storm slabs could become 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

An icon showing 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.Minimize exposure to solar aspects overhead, loose avalanches could travel surprisingly far.Stay in tune with the physical environment, conditions may change throughout the day.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

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