Avalanche Forecast

Issued: Jan 23rd, 2013 9:17AM

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

triley, Avalanche Canada

Kootenay Boundary.

The snow drought is over! Avalanche Danger is trending up as the new storm slab develops. It’s time to adjust your goals to reflect the increasing danger.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

Overnight and Thursday: 5-10 cms of snow combined with Westerly winds building to moderate values overnight. Flurries or light snow during the day accumulating another 3-5 cms. Freezing level at valley bottoms and alpine temperatures about -10.0.Friday: Another 5-10 cms is expected during the day combined with strong Westerly winds.Saturday: Continued light snowfall combined with light Westerly winds.

Avalanche Summary

Expect wind and storm slab avalanche activity to pick up with stormy weather throughout the forecast period.

Snowpack Summary

Large surface hoar growth and surface faceting continues in sheltered and shady areas, open unprotected areas are highly wind-affected, while sun-exposed slopes have been subject to melt-freeze cycles. All of these current snow surfaces will likely provide a poor bond once buried, and will be especially concerning when and where a sufficiently deep and cohesive slab develops. The persistent weakness buried early January recently produced moderate sudden planar compression test results where is was found down 45cm on a steep north facing alpine slope. However, in general, this persistent weakness is much deeper and no longer reacting in snowpack tests.

Problems

Storm Slabs

The new snow may be sitting on a hard layer like an old wind slab or a sun-crust. There may also be a weak layer of surface hoar or facets sandwiched between the new snow and the old surface. Pockets of deep soft new wind slab may also be found.

Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Jan 24th, 2013 2:00PM