Avalanche Forecast

Issued: Mar 2nd, 2019 4:53PM

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

mbender, Avalanche Canada

Kootenay Boundary.

Wind slabs continue to be reactive at upper elevations. A persistent slab problem still exists in the region and has been responsible for sporadic human triggered avalanches over the past week.

Summary

Confidence

High - The weather pattern is stable

Weather Forecast

SUNDAY: Mainly sunny / light east wind / alpine temperature -13 CMONDAY: Mainly sunny / light to moderate east wind / alpine temperature -10 CTUESDAY: A mix of sun and cloud / light to moderate east wind / alpine temperature -7 C

Avalanche Summary

There is an excellent MIN post describing a skier triggered size 1.5 persistent slab avalanche on Saturday. Click here to see it. Additionally on Saturday reports indicate a few size 1-1.5 wind slab avalanches on west aspects in the alpine and treeline. There were reports of several size 1-1.5 explosives triggered storm slab avalanches on Friday in the alpine and tree line on northerly aspects. On Thursday, dry loose sluffing was seen in steeper terrain features.

Snowpack Summary

The surface consists of 15-30 cm of low density new snow. This new snow may have a poor bond to the previous firm wind slabs and faceted (sugary) snow surfaces. A layer of feathery surface hoar sitting on a crust that was buried on February 7th is now 30-50 cm deep. Two other surface hoar layers are buried 50 to 80 cm down (referred to as the February 1st and mid-January layers) remain reactive in snowpack tests.

Problems

Wind Slabs

Most recent wind slab formation is on south and west facing slopes, however wind slabs likely exist on all aspects due to changing winds.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in freshly wind-loaded features, especially near ridge crests and in steep terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

It remains possible to trigger an avalanche on one of the surface hoar or crust layers buried 30 to 80 cm deep. These layers seem to be most prominent at treeline.

Caution around sheltered open areas treeline and below.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use increased caution on open slopes and convex rolls at lower elevations.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Mar 3rd, 2019 2:00PM