Avalanche Forecast

Issued: Mar 19th, 2018 4:13PM

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

ghelgeson, Avalanche Canada

Kootenay Boundary.

It is a good time to be traveling in the mountains, but remember that low danger does not mean no danger. Loose wet avalanche activity should be limited Tuesday, but stubborn old wind slabs and large cornices demand our respect.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

Tuesday offers a bit of a drying trend for most of the province. A low approaching from the Gulf of Alaska may bring some precipitation to the region beginning Wednesday afternoon.TUESDAY: Broken cloud cover with a bit of clearing in the afternoon, freezing level beginning at 600 m rising to 1500 m, moderate southwest wind, trace of precipitation possible. WEDNESDAY: Few clouds initially with scattered cloud cover building in the afternoon, freezing level beginning at 600 m rising to 1600 m, light to moderate southerly wind, trace of precipitation possible.THURSDAY: Overcast, freezing level beginning around 1200 m rising to 1900 m, strong southerly wind, 8 to 15 mm of precipitation possible.

Avalanche Summary

No significant avalanche activity to report from Saturday or Sunday.Avalanche activity on Friday was limited to snowballing on solar aspects.On Thursday small loose avalanches were reported on steep features as the new snow ran on a crust. A few small skier triggered wind slabs were also reported from east facing alpine terrain.

Snowpack Summary

A crust has formed on all solar aspects. Fresh surface hoar has begun to form on polar aspects (those that face north and east) near ridgetop.About 5 cm of snow is between the surface and another interface that mirrors the surface; crust on solar, surface hoar on high elevation north.Snow that fell March 8th/9th was redistributed by west/southwest wind, forming wind slabs at high elevations. These wind slabs rest on a layer of surface surface hoar about 25 to 40 cm below the surface which has not been recently reactive.A mix of weak layers exist 50 to 100 cm below the surface, including small surface hoar on shady aspects and a crust on solar aspects. These layers are expected to have gained strength from recent cycles of warming and cooling. Like other deeper weak layers that formed in January and December, they are considered dormant at this time. These deeper layers include several surface hoar and facet layers 1 to 2 m below the surface and a crust/ facet interface near the base of the snowpack.

Problems

Wind Slabs

It is a good time to be traveling in the mountains. Increased cloud cover should put the brakes on loose wet activity. Use normal caution and be aware that small wind slabs near ridge crest may be sensitive to human triggering.

Be careful with wind loaded pockets, especially near ridge crests and in extreme terrain.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Give cornices a wide berth when travelling on or below ridges.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Mar 20th, 2018 2:00PM