Avalanche Forecast

Issued: Apr 3rd, 2015 9:03AM

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

pgoddard, Avalanche Canada

Cariboos.

The persistent slab problem is shifting into a low-probability/ high-consequence situation. Be confident in your local snowpack before committing to any big terrain.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

Light snow fall (5-15 cm) is expected on Saturday and Sunday, petering to flurries on Monday, with a chance of sun. The freezing level is around 1500 m by day, falling towards valley floor by night. Winds are generally light.

Avalanche Summary

A handful of recent large avalanches have been reported over the last few days. Many of these have been on north aspects, with the odd event on other aspects. There has also been a number of cornice falls.

Snowpack Summary

Recent squally snow showers have brought 10-25 cm of snow, which has been shifted into wind slabs. This new snow sits above a crust which varies in thickness with elevation. Cornices are large and should be given a respectful berth.Two crust/facet interfaces, formed in March and February, sit about 80-120 cm deep in the snowpack. These weaknesses are becoming more stubborn to trigger, but still react in snowpack tests and have potential for wide propagations and very large avalanches if triggered. Most likely trigger spots would be thin snowpack areas, or with a large load like a cornice fall.Basal facets are on operators' list of concerns. Deep snowpack issues sometimes wake up in the spring, so should not be forgotten.

Problems

Wind Slabs

Recent winds have shifted snow into wind slabs on lee and cross-loaded slopes. These may be buried by new snow. Cornices are large and fragile.

Give cornices a wide berth when travelling on or below ridges.>Use ridges or ribs to avoid areas of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

Buried persistent weak layers may still be reactive to human-triggering and large avalanches remain possible. Smaller avalanches in motion or a cornice failure could step down to one of these deeper layers.

Dig down to find and test weak layers before committing to a big line.>Caution around convexities or areas with a thin or variable snowpack.>Choose conservative lines.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Apr 4th, 2015 2:00PM