Avalanche Forecast

Issued: Mar 7th, 2019 4:24PM

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

mconlan, Avalanche Canada

Kootenay Boundary.

Variable snowfall amounts accumulated across the region. The snow may be reactive on Friday, either as soft slabs or loose snow. The persistent slab problem still exists and is best controlled by diligent group management.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

THURSDAY NIGHT: Cloudy with light snowfall, accumulation 1 to 3 cm with locally higher amounts from a convective nature, moderate southwest wind, alpine temperature -12 C.FRIDAY: Cloudy with isolated snowfall, trace accumulation, light to moderate west wind, alpine temperature -11 C.SATURDAY: Cloudy with isolated snowfall, trace accumulation, light south wind, alpine temperature -10 C.SUNDAY: Mostly clear skies, light northwest wind, alpine temperature -9 C, freezing level 1300 m.

Avalanche Summary

No new avalanches were observed on Wednesday.

Snowpack Summary

Around 10 cm of recent snow overlies wind-affected snow in exposed terrain, soft and faceted snow in sheltered areas, and a melt-freeze crust on southerly aspects.Two layers of weak and feathery surface hoar crystals are buried in the snowpack between 40 and 80 cm deep, which were buried mid-February and early-February. The layers may be associated with a melt-freeze crust on southerly aspects. These layers remain reactive in snowpack tests and have produced sporadic avalanches in the region over the past week.

Problems

Wind Slabs

The recent snow fell with variable winds, creating new slabs in exposed terrain. Use added caution in lee terrain features, particularly if you find locally deep deposits. The snow may be loose and reactive in steep, sheltered terrain.

Assess the bonding of the new snow with underlying layers as you travel.Recent new snow may be hiding wind slabs that were easily visible before the snow fell.Use caution in freshly wind-loaded features, especially near ridge crests and in steep terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Two layers of weak surface hoar and/or a crust are buried 40 to 80 cm. These layers have recently been the most active between 1700 m and 2200 m and on southwest to southeast aspects. The problem is best controlled with appropriate group management.

Choose moderate-angled terrain with low consequence, avoiding terrain traps.Apply caution around sheltered and open areas at treeline and below. Space out to limit exposure.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 8th, 2019 2:00PM