Avalanche Forecast

Issued: Apr 9th, 2013 10:45AM

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

jlammers, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain on Wednesday

Weather Forecast

Wednesday: Moderate to locally heavy snowfall starting Tuesday night and continuing Wednesday / Moderate northwest winds / Freezing level at 1500mThursday: Light snowfall / Moderate northwest winds / Freezing level at 1200m Friday: Light snowfall intensifying throughout the afternoon / Light south winds / Freezing level at 1000m

Avalanche Summary

On Monday a couple of slab avalanche to size 2.5 were remotely triggered by a skier from 300m away. The avalanches occurred on a northwest aspect in the high alpine. The early April surface hoar/ facet interface is though to be the culprit.

Snowpack Summary

At upper elevations 20-45cm of recent snow is covering a crust or moist snow. At the same interface you may find a touchy layer of facets or surface hoar on shaded high alpine slopes. Where they exist, these weak crystals have been responsible for large remote triggers. The variable and reactive nature of this layer suggests that it may continue to catch people by surprise. I'd dig down and test for this weakness before committing to any exposed alpine terrain.At lower elevations (below 1700m) rain has made the snow surface wet or moist. Recent snowfall combined with wind have made large cornices even bigger.

Problems

Storm Slabs

Steady snowfall on Wednesday will add to an existing storm/ wind slab problem. Storm slabs may be particularly touchy in wind-affected terrain, or in spots where they overlie weak and reactive surface hoar crystals.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be aware of the potential for large avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 5

Loose Wet

Rain at lower elevations will promote ongoing wet snow instabilities. Watch for loose wet avalanches on steep slopes, or glide cracks in terrain with smooth ground cover.

Watch for wet loose or slab activity with forecast rain and/or warm temperatures.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 10th, 2013 2:00PM