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Avalanche Forecast

Jan 5th, 2018–Jan 6th, 2018
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: South Coast Inland.

Wind stiffened storm slabs are expected to form Friday night into Saturday at upper elevations. These slabs may be resting on a slight crust which could make them that much more sensitive to human triggering.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

A couple of weak residual lows will bring patchy light precipitation to the South Coast Inland through the weekend.SATURDAY: Overcast, freezing level around 1000 m, strong west/southwest wind, 1 to 4 mm of precipitation expected.SUNDAY: High cloud, freezing level around 800 m, light south wind, trace of precipitation expected.MONDAY: High cloud, freezing level around 900 m, light south wind, 1 to 2 mm of precipitation expected.

Avalanche Summary

No new avalanche activity to report from Thursday. On Wednesday numerous loose avalanches to size 1.5 were observed from south aspects at all elevations. On Tuesday reported avalanche activity was limited to snow balling and pin wheels on north aspects.

Snowpack Summary

Warm temperatures likely produced a few millimeters of rain as high as 2000 m on Friday, this likely occurred throughout the region. Previous to Friday's rain event, warm alpine temperatures had allowed the upper 5 cm of the snowpack to become moist, even on upper elevation northeast facing features. As temperatures cool Friday night a crust is expected to form on the surface.On December 28th and 29th two successive storms produced 50 to 80 cm of snow. On December 29th and 30th strong to extreme winds out of the southwest, south and southeast created widespread wind effect. Time and warm temperatures allowed this snow to settle and bond well with 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.

Avalanche Problems

Storm Slabs

Light snowfall coupled with strong winds out of the southwest will likely form wind stiffened storm slabs in lee terrain. These slabs may be sitting on a thin crust which could increase their sensitivity to human triggering.
Use ridges or ribs to avoid pockets of wind loaded snow.Storm slabs may become more sensitive to human triggering throughout the day.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2