Avalanche Forecast

Issued: Jan 8th, 2018 5:17PM

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

Avalanche Canada ghelgeson, Avalanche Canada

A few centimeters of snow accompanied by continued southwest wind Monday night will add to recently formed wind slabs that rest on a thin crust in many terrain features. The presence of crust may enhance the slabs sensitivity to human triggering.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

Continued precipitation is expected through Monday night before a brief lull in the action Tuesday and Wednesday. Thursday's system has potential to be juicy, but there is a lot of discrepancy surrounding how much precipitation it will deliver. Stay tuned for details. MONDAY NIGHT: Overcast, freezing level around 900 m, moderate southwest wind, 1 to 5 cm of snow.TUESDAY: Overcast, freezing level around 1000 m lowering through the day, moderate west/southwest wind, trace of snow expected.WEDNESDAY: Overcast, freezing level at valley bottom, light scattered wind, trace of snow possible, 1 to 10 cm possible Wednesday night.THURSDAY: Overcast, freezing level may rise as high as 800 m, strong southwest wind, 10 to 20 cm of snow possible.

Avalanche Summary

Not much to report in the way of recent avalanche activity. On Sunday a small size 1 natural avalanche and a couple small skier controlled avalanches were reported from unknown aspects/elevations. These were likely small storm slabs running above the recently formed crust.

Snowpack Summary

10 to 20 cm of recent storm snow now rests on the the January 6th crust. This crust formed after temperatures cooled on Saturday, locking up the previously moist surface snow. On Sunday moderate southwest winds likely formed wind stiffened soft slabs in lee features at and above treeline. Two successive storms at the end of December produced 50 to 80 cm of snow, which has long since settled and bonded to the underlying surface. A widespread melt-freeze crust formed in mid-December may still be an issue in the northern portion of the region where it's down 50 to 100 cm below the surface, but is likely trending towards dormancy. Around the Coquihalla this interface is now thought to be part of a well bonded mid-pack. The lower snowpack is generally strong and well settled.

Problems

Wind Slabs

An icon showing Wind Slabs
Continued light snowfall coupled with moderate winds out of the southwest will likely form wind slabs in lee terrain. These slabs may be sitting on a thin crust which could increase their sensitivity to human triggering.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 2

Valid until: Jan 9th, 2018 2:00PM