Avalanche Forecast

Issued: Mar 28th, 2016 8:22AM

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

pmarshall, Avalanche Canada

Cariboos.

Expect avalanche danger to rise during the day, particularly on sun-exposed slopes. Plan to start your day early and move away from large sun-drenched slopes during the heat of the day.

Summary

Confidence

Moderate

Weather Forecast

WEATHER SUMMARY: It will be a sunny and warm week! Temperatures will steadily climb each day with the freezing level reaching at least 2400 m by Thursday (treeline temps near +4). Ridge winds should be generally light from the NW-NE.

Avalanche Summary

No new slab avalanches were reported on Saturday or Sunday. On Friday there were 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 steep unskiable terrain.

Snowpack Summary

Up to 15 cm of new snow fell on Sunday, which was probably quickly affected by the sun on solar aspects (melt-freeze cycle), and northerly winds in exposed alpine terrain. There are several thin crusts in the upper snowpack on all but shaded north aspects. 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

Storm Slabs

Strong sunshine and warming could make recent storm slabs sensitive to triggering, particularly on southerly aspects where new snow overlies a solid crust and recent wind-loading may have occurred.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Intense spring sun and rising temperatures could reactivate buried persistent weaknesses in the upper snowpack.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Choose well supported terrain without convexities.>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

Cornices

Tread cautiously near large overhanging cornices. Weak cornices could pop off naturally, potentially triggering large slabs on the underlying slope.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Mar 29th, 2016 2:00PM