Avalanche Forecast

Issued: Apr 22nd, 2014 9:15AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Loose Wet and Deep Persistent Slabs.

esharp, Avalanche Canada

Cariboos.

This forecast was build on limited field reports. If you head out into the mountains please tell us about the conditions you found. Send your observations to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: Southerly flow will continue to generate precipitation over the southern interior, Thursday will see drier conditions before an approaching trough off the coast forces a southerly flow pattern again on Friday. Tonight and Wednesday: Light precipitation continuing through the night up to 20 cm of snow at upper elevations. / Moderate westerly winds / Freezing levels falling to 1600mThursday: Sunny with cloudy periods and chances of flurries / Light southerly winds / Freezing levels 2000mFriday: Flurries / light southeasterly winds / Freezing levels 2000m

Avalanche Summary

Small slabs have been recently triggered naturally and by skiers in areas where the upper snow is moist and sits above a crust. At lower elevations and on solar aspects small to large loose wet avalanche continue to be triggered on steep slopes. 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

New snow is falling on a fresh melt freeze crust on all but high elevation North aspects.Below this 10 to 30cm of snow overlies older melt-freeze crusts from earlier in the month. Wind slabs can be found in lee features on N and E aspects in the Alpine.Several persistent weak layers still exist in the highly variable snowpack of the region:-The mid-March sun crust/surface hoar layer down 50-80cm and the early-March crust/facet/surface hoar layer down around 80-120cm seem to be laying dormant for the time being.-The mid-February crust/facet/surface hoar combo is typically down 60 - 120cm. Direct triggering of this layer has become unlikely, however, cornice fall, a smaller avalanche in motion or prolonged warming may wake this layer up. The resulting avalanche would be very large and destructive.

Problems

Storm Slabs

Expect to see an increase in avalanche activity where rain affects previously dry snow. At higher elevations expect winds slabs will form on north aspects.

Avoid avalanche terrain during periods of rain.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

Expect to see an increase in loose avalanche activity were the forecast rain saturates the upper snowpack.

Avoid steep, open glades in the forest.>Avoid slopes with glide cracks.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

4 - 7

Valid until: Apr 23rd, 2014 2:00PM