Avalanche Forecast

Issued: Mar 29th, 2016 8:51AM

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

triley, Avalanche Canada

Cariboos.

Special Public Avalanche Warning for this region. Forecast very warm temperatures, high freezing levels, and strong solar radiation will increase the avalanche danger.

Summary

Confidence

High

Weather Forecast

Clear skies and very warm daytime temperatures are forecast for the remainder of the week; freezing levels should reach at least 2500 metres. Winds are expected to be light from the west or northwest. There should be some radiative cooling overnight that may develop surface crusts, but the warm air mass may break these crusts down very early in the day.

Avalanche Summary

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

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

Cornices

Forecast high freezing levels, very warm daytime temperatures, and strong solar radiation are expected to result in natural cornice falls. Large cornice falls in motion may release deeply buried weak layers resulting in very large avalanches.

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

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Loose Wet

High daytime temperatures and strong solar radiation may result in natural loose wet avalanches at all elevations. Avoid sun exposed slopes if the snow is moist or wet.

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

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

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

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Choose well supported terrain without convexities.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Mar 30th, 2016 2:00PM