Avalanche Forecast

Issued: Mar 9th, 2014 10:43AM

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

jlammers, Avalanche Canada

Cariboos.

The storm may be tapering off, but touchy conditions may persist with higher freezing levels and the possibility of sun over the forecast period.

Summary

Confidence

Fair - Freezing levels are uncertain on Monday

Weather Forecast

Monday: Light snowfall / Moderate westerly winds / Freezing level at 1500mTuesday: Generally overcast skies with possible sunny breaks / Moderate northwest winds / Freezing level at about 1500mWednesday: Light snowfall with a chance of sunny breaks / Moderate westerly winds / Freezing level between 1500m and 2000m

Avalanche Summary

Avalanche observations were extremely limited on Saturday; however, I can only imagine there would have been a significant round of storm slab/ loose wet activity in response to heavy snowfall, wind and rain on Saturday.

Snowpack Summary

A potent storm slab which formed in recent days overlies small surface hoar crystals in sheltered areas and a sun crust on previously sun-exposed slopes. Wind and warming have added to the reactivity and destructive potential of the new snow which may be particularly reactive where it overlies the crust. Rain at lower elevations has likely saturated the snowpack. There is ongoing concern for a mix of weak surfaces which were buried on February 10th. This persistent interface lies over a metre below the surface, and includes weak surface hoar, well developed facets and a mix of hard surfaces which remain widespread at all aspects and elevations. For the most part, the mid and lower snowpack are strong and well consolidated. Weak basal facets exist in some areas, but triggering is unlikely.

Problems

Storm Slabs

The region was hit hard on Saturday receiving about 40cm of snow over a 24 hour period. Storm slabs may be especially touchy where they overlie a buried crust.

The new snow will require several days to settle and stabilize.>Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Deep Persistent Slabs

The early February weak layer may be stubborn to trigger, but long fracture propagations may still result if a large force such as a storm slab in motion or a cornice fall steps down to the persistent weak layer.

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Loose Wet

The snowpack has been saturated by rain at lower elevations. Watch for pushy loose wet avalanches in steep terrain below treeline.

Be cautious of wet sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 10th, 2014 2:00PM