Avalanche Forecast

Issued: Mar 27th, 2016 3:00PM

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

jlammers, Avalanche Canada

Kootenay Boundary.

Give the new snow time to stabilize before committing to big terrain. The Avalanche Danger may change quickly in the spring. Even brief periods of sun can trigger pushy loose wet avalanches or promote destructive cornice falls.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Sunday

Weather Forecast

10-15cm of new snow is forecast for Sunday night while lingering flurries are expected on Monday. On Tuesday and Wednesday the region will see mainly sunny skies as a ridge of high pressure develops over the province. Ridgetop winds should be moderate from the west on Sunday night, becoming moderate and northerly by Monday afternoon. On Tuesday and Wednesday, winds will be light. Freezing levels will sit at about 1700m on Monday, and then rise to about 2000m on Tuesday and Wednesday.

Avalanche Summary

No new avalanches were reported on Saturday. A new round of storm slab activity is expected in response to new snow and moderate winds on Sunday. Storm slab activity may persist for longer than usual due to underlying surface hoar. If the sun comes out on Sunday, loose wet avalanche activity can also be expected in steep, sun-exposed terrain.

Snowpack Summary

As of Sunday morning, 1-8cm of new snow sat above small surface hoar on shaded slopes and a melt-freeze crust on sun-exposed slopes. About 35cm below the surface, you'll likely find another hard crust which exists everywhere except high, north-facing terrain. The late February persistent weak layer down 70 to 120 cm remains a low probability / high consequence concern. Test results are variable, with occasional sudden planar (pop) results. While generally becoming unlikely to trigger, this layer could wake up with a cornice fall, warm temperatures or from a thin snowpack area. Cornices are large and looming in some areas.

Problems

Storm Slabs

Snow and wind on Sunday night will form new storm slabs which should be touchiest in higher elevation, wind-exposed terrain. If the sun makes an appearance, loose wet avalanches will also become a concern in sun-exposed terrain.

Be cautious as you transition into wind affected terrain.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Large fragile cornices threaten many slopes. A cornice fall could be the large trigger required to awaken deeper weak layers.

Give cornices a wide berth when travelling on or below ridges.>Do not travel on slopes that are exposed to cornices overhead.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Mar 28th, 2016 2:00PM