Avalanche Forecast

Issued: Mar 26th, 2016 8:52AM

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

pmarshall, Avalanche Canada

Cariboos.

Triggering lingering storm slabs and fresh wind slabs is possible on Sunday, mainly from steep, north-facing alpine terrain.

Summary

Confidence

Moderate

Weather Forecast

SUNDAY: Periods of snow – around 5-10 cm. The freezing level is around 1400 m. Winds are moderate from the W-SW. MONDAY: A mix of sun and cloud. The freezing level climbs to 1800 m and winds ease to light. TUESDAY: Mainly sunny. The freezing level is around 1800-2000 m and winds are light.

Avalanche Summary

On Friday there were numerous reports of skier-controlled avalanches up to size 1.5 from steep wind-loaded alpine terrain. There were also a few size 2-3 natural cornice releases. On Thursday, we had reports of storm slab avalanches up to size 2.5 in isolated steep unskiable terrain.

Snowpack Summary

Up to 40 cm of recent storm snow has accumulated with thin new wind slabs in lee terrain, and a possible sun crust on solar aspects. Moist snow was reported on solar aspects in the alpine, and up to at least 1800 metres on shaded aspects. There are several thin crusts in the upper snowpack on all but shaded north aspects. 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 during periods of strong solar radiation and/or daytime warming.

Problems

Storm Slabs

Storm slabs are lingering, and a bit of new snow and wind on Sunday could lead to fresh wind slab development in exposed lee terrain.

Be alert to conditions that change with elevation.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Cornices remain an ongoing concern. Cornice falls may trigger deeply buried persistent weak layers.

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

Possible

Expected Size

2 - 5

Persistent Slabs

A persistent weak layer of buried surface hoar, facets, and crusts is buried down close to a metre. This has become a low probability of triggering, but high consequence of large avalanche problem.

Choose well supported terrain without convexities.>Use conservative route selection, stick to moderate angled terrain with low consequence.>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

Expected Size

3 - 6

Valid until: Mar 27th, 2016 2:00PM