Avalanche Forecast

Issued: Apr 1st, 2016 9:07AM

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

triley, Avalanche Canada

Cariboos.

Special Public Avalanche Warning extended for this region. Continued strong solar radiation and high freezing levels will keep the avalanche danger elevated.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

The ridge of high pressure that is responsible for the clear skies and very warm temperatures is slowly starting to move eastward. Freezing levels should drop a bit, but will remain above 2500 metres overnight and morning sun should quickly break down any crusts that develop. High cloud is expected to move into the interior ranges by Saturday afternoon. Moderate westerly winds on Saturday night combined with light precipitation may not drop freezing levels more than a few hundred metres, and may inhibit crust formation overnight. Sunday should be mostly sunny with light winds and freezing levels at 2500 metres. Freezing levels should begin to drop by Monday morning, when moderate southwest winds and precipitation move inland from the coast.

Avalanche Summary

Numerous solar releases up to size 2.0 were reported on Thursday. On Wednesday, loose wet avalanches were reported up to size 2. On Tuesday numerous natural cornice releases resulted in avalanches up to size 3.0 from various aspects in the alpine. On Monday we had reports of several natural cornice falls up to size 2.0 from various aspects in the alpine. There were also several loose moist or wet avalanches up to size 2.0 on solar exposed aspects in steep terrain in the late afternoon.

Snowpack Summary

New surface crusts have developed at all elevations on solar aspects and on all but high alpine elevations on shaded aspects. Thin surface crusts may break down early with continued warm temperatures. Approximately 30-50 cm of settled storm snow sits on a melt-freeze crust buried on Mar. 20. The late February persistent weak layer continues to be a concern for wide propagations in isolated terrain, however it may take a large trigger like a cornice fall to initiate an avalanche. Watch for recent storm snow releasing as loose wet avalanches on steep solar aspects with strong solar radiation and daytime warming this week.

Problems

Cornices

Continued high freezing levels and very warm daytime temperatures are very likely to result in natural cornice falls. Large cornice falls may trigger buried weak layers resulting in very large avalanches.

Avoid steep slopes below cornices.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Loose Wet

Forecast high freezing levels and very warm daytime temperatures may break down surface crusts early and result in loose wet avalanches from steep solar aspects. Wet slab avalanches are possible if loose snow propagates on a buried crust.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Be alert to conditions that change with elevation.>

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

Continued warm and sunny weather may add enough heat to the snowpack to “wake-up” persistent weak layers buried in the snowpack. Rapid warming of the winter snowpack can result in deeply buried weak layers propagating very large avalanches.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Apr 2nd, 2016 2:00PM