Avalanche Forecast

Issued: Mar 13th, 2014 10:04AM

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

ghelgeson, Avalanche Canada

Cariboos.

The current snowpack presents a serious challenge. Check out our latest blog for a look into the recent avalanche cycle and our best guess into what the future holds.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain on Saturday

Weather Forecast

Synopsis: A quick hitting system passes over the region Friday before a significant and warm rain/snow event arrives Saturday night and then settles in Sunday. Precip amounts and freezing Levels vary significantly from one model to the next, thus overall confidence in this Wx is Fair. Friday: Freezing Level: 1000m - 1500m; Precip: 2/8mm - 2/10cm; Treeline Wind: Light, SW | Mod W at ridgetop.Saturday: Freezing Level: 1100m - 1600m; Precip: Nil; Wind: Mod, SWSaturday Night: Freezing Level: 1000m - 1600m; Precip: 4/16mm - 4/20cm; Treeline Wind: Strong, W | Extreme SW at ridgetop.Sunday: Freezing Level: 1000m - 1600m; Precip: 1/5mm - Trace/5cm; Treeline Wind: Mod, W | Extreme SW at ridgetop.

Avalanche Summary

Riders remote triggered avalanches to size 2 on steep NE facing slopes at treeline Wednesday. One natural size 3 on a relatively steep NE facing bowl feature was also observed, likely failing on the February 10th PWL.The group involved in a very close call with a size 3.5 avalanche in the Ozalenka Valley south of McBride submitted a great incident report.Â Check it out here.

Snowpack Summary

Up to 80 cm of recent storm snow rests on small grained surface hoar in sheltered areas and a sun crust on solar aspects. In upper elevation wind exposed terrain the new snow has been pushed into deep wind slabs by moderate SW winds.The freezing levels remain high (aprox. 1800m) in this spring like pattern. Below treeline the snowpack is seeing a daily melt freeze cycle that has left many features wet and sloppy by the afternoon. This has created an isolated wet slab problem that has been responsible for serious incidents recently. At ridgetop cornices are large and unsupported.The February 10th surface hoar/facet/crust combo is around a meter below the snow surface and widespread throughout the region. Surface avalanches in motion, cornice fall and/or solar radiation all have the potential to initiate an avalanche on this deeply buried weak layer. Interestingly, we continue to hear about remote triggering at this interface. For the most part, the mid and lower snowpack are strong and well consolidated.

Problems

Storm Slabs

New snow and wind Friday will refresh the surface and hide the old slab just out of sight. Unfortunately, the old slab remains sensitive to human triggering, and the entire snowpack is still adjusting to all the warmth of the last week.

Minimize exposure during periods of heavy loading from new snow, wind.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be careful to keep storm day fever from luring you out into bigger terrain features.>The snowpack still needs time to adjust to the recent warm temps and rain. Keep it reigned in.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

The early February Persistent Weak Layer is still active and has produced some stunning avalanches recently. Very large avalanches may result from a storm slab in motion, a cornice fall or a rider finding the sweet spot.

Be aware of the potential for large, deep avalanches due to the presence of deeply buried weak layers.>Avoid rock out croppings, large convexities and anywhere the snowpack is thin and/or variable.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Mar 14th, 2014 2:00PM