Avalanche Forecast

Issued: Apr 27th, 2014 9:06AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs, Loose Wet and Deep Persistent Slabs.

swerner, Avalanche Canada

Kootenay Boundary.

We are no longer issuing danger ratings for this region due to a lack of field data. Check out this forecasters blog post for more insight into managing the current conditions.

Summary

Weather Forecast

Synopsis: A strong upper ridge will build over the region on Monday and dominate through the week. This will bring mostly sunny skies, and moderate SW-W ridgetop winds. Freezing levels will rise to 1800 m on Monday and then climb steadily above 2000 m from Tuesday onward. No significant overnight freeze is expected.

Avalanche Summary

Expect loose wet avalanches in steep terrain if it is raining or during sunny periods, especially if the sun or rain is affecting the fresh snow. Spring squalls may bring locally heavy precipitation and new storm or wind slabs may develop in higher terrain if you see significant new snow accumulation. Cornices collapses have been reported during periods of daytime warming. Occasionally these heavy triggers have caused large deep slab avalanches on the slopes below.

Snowpack Summary

This is a broad general summary of conditions in the region based solely on recent weather data and previous snowpack information. It should be supplemented with local observations to help assess avalanche danger. Please refer to this document for additional snow and avalanche information and general travel advice. Over the last few days we have seen moderate amounts of moist or wet new snow mixed with showers or periods of rain below 1600-1800 m. Westerly winds have likely formed pockets of wind slab at higher elevations in lee of ridges and terrain features. The late January/early February persistent weak layer is deeply buried but could still wake up during periods of heavy precipitation (especially rain) or significant warming and solar radiation. Be particularly wary of this on large open alpine slopes. Cornices are large in some areas and should be given a wide berth.

Problems

Wind Slabs

New snow amounts are extremely variable across the region with the highest amounts falling in the south. Moderate winds have redistributed new snow and wind slabs may be found in lee features. Expect touchy conditions when the sun comes out.

Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

Expect loose wet avalanches in steep terrain if it is raining or during sunny periods, especially if the sun or rain is affecting fresh snow.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

The potential for very large deep slab avalanches needs to remain on your radar. Cornice fall, warming temperatures or a smaller wet or wind slab avalanche in motion could act as triggers.

Pay attention to overhead hazards like cornices.>Be aware of the potential for large, deep avalanches due to the presence of buried persistent weak layers.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 5

Valid until: Apr 28th, 2014 2:00PM