Avalanche Forecast

Issued: Jan 4th, 2018 5:08PM

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

ghelgeson, Avalanche Canada

South Coast Inland.

The current forecast calls for very little rain, but each run of the weather models shows more rain than the previous. Despite the recent warm temperatures, the effect of rain on snow could be dramatic. Watch for rapidly changing conditions Friday.

Summary

Confidence

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

Weather Forecast

Friday looks to be a pretty funky meteorological period. The good news is that we are expected to return to a more typical stormy winter pattern. The bad news is that we have to endure some rain, perhaps even some freezing rain, before we get back to the snow on Saturday. FRIDAY: Overcast, light inversion with above freezing temperatures between 1500 m and 2600 m, cooler air in the valleys, moderate to strong southerly wind, 1 to 2 mm of precipitation which may fall as freezing rain.SATURDAY: Overcast, freezing level around 800 m, light to moderate southwest wind, 1 to 3 mm of precipitation expected.SUNDAY: Decreasing cloud cover, freezing level around 800 m, light southwest wind, trace of precipitation expected.

Avalanche Summary

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

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. 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 have allowed this snow to settle and bond well with the underlying surface. The exception may be with wind slabs in more extreme terrain and isolated pockets of buried surface hoar below treeline. A widespread melt-freeze crust may still be an issue in the northern portion of the region where it's down 50 to 70 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

Storm Slabs

Friday may bring rain or even freezing rain at all elevations. The most dramatic effect will likely be on high elevation north facing slopes, but prolonged rain could initiate widespread natural avalanches on all aspects and elevations.

Avoid avalanche terrain during periods of heavy rain.The first few hours of rain will likely be the most dangerous period

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 5th, 2018 2:00PM