Avalanche Forecast

Issued: Mar 27th, 2016 8:17AM

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.

Warming and sunshine will drive avalanche danger this week. Plan to start your day early and to avoid large sun-drenched slopes during the heat of the day.

Summary

Confidence

High

Weather Forecast

MONDAY: Cloudy with a chance of flurries early, then sunny breaks. The freezing level climbs to 1600-1800 m and winds are moderate from the N-NE. TUESDAY: Becoming sunny. The freezing level is around 1800-2000 m and winds are light to moderate from the North. WEDNESDAY: Mainly sunny. The freezing level spikes above 2200 m. Ridge winds are generally light to moderate from the North.

Avalanche Summary

No new slab avalanches were reported on Saturday. 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

Light new snow covers a melt-freeze crust on solar aspects and all aspects below treeline, dry snow on sheltered shady slopes, and wind affected snow in higher exposed 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 during periods of strong solar radiation and/or daytime warming.

Problems

Storm Slabs

Forecast strong northerly winds could create new wind slabs on solar aspects, which could become very touchy if the sun makes an afternoon appearance.

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: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

A buried persistent weakness, around 60-100 cm deep, could reactivate with strong spring sunshine and climbing temperatures this week.

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

Expected Size

3 - 6

Cornices

Natural cornice falls are likely during periods of strong solar radiation and warm daytime temperatures. Cornice falls may trigger deeply lurking persistent weak layers.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Mar 28th, 2016 2:00PM