Avalanche Forecast

Issued: Dec 5th, 2014 8:54AM

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.

ghelgeson, Avalanche Canada

South Rockies.

Forecast confidence is very poor, we desperately need your observations right now. Please email them to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: A pattern shift is underway as dry and cold northwest flow gives way to rather mild southwest flow. Storm totals through the weekend look pretty bleak for the Rockies, but the door appears to be open to a succession of storms through the middle of next week.Saturday: Freezing Level: 500m with potential for above freezing temps between 1000m and 2000m; Precipitation: 1-3mm | Trace; Wind: Treeline: Moderate to Strong, SW | Ridgetop: Extreme, SW Sunday: Freezing Level: 1300m; Precipitation: 0-2mm | trace-2cm; Wind: Treeline: Moderate, SW | Ridgetop: Strong, W/SWMonday: Freezing Level: 1800m; Precipitation: Nil | Trace; Wind: Treeline: Moderate to Strong, SW | Ridgetop: Strong, SW

Avalanche Summary

No avalanche activity reported. Have you seen anything recently?

Snowpack Summary

As we begin our forecasting season, we are working with almost no field data. If you have been out in the mountains, we'd love to hear from you. There is at least one, maybe more, problematic layers in the South Rockies snowpack. Last weekends 30 - 60cm of storm snow buried a weak layer of facets over a crust which formed during November's dry spell. That interface is probably around a meter down now. Not much us known about the reactivity of this layer, nor the slab above it. But, it doesn't take much of a leap of faith to understand that a meter deep slab sitting on a persistent weak layer is a potentially bad thing.This forecast isn't going to get much better until we get some field observations. If you've got some, please send them in. Eventually you'll be able to use the Mountain Information Network, but for now please email your obs to: forecaster@avalanche.ca THANKS!

Problems

Wind Slabs

Strong to Extreme SW winds will likely transport snow into fresh wind slabs which may extend further down the slope than usual.

Avoid freshly wind loaded features.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

A weak layer of facets buried a meter deep may fail when overloaded by a skier, sledder or wind transported snow. Forecasted warming may increase sensitivity to human triggering. Avalanches on this layer could be surprisingly large.

Every avalanche has the potential to step down to the ground right now, you need to manage your behavior and terrain use to account for that possibility.>Avoid spots where you're more likely to trigger large avalanches: thin spots, rock out-croppings, convex rollers and broad planar slopes without anchors like trees.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Valid until: Dec 6th, 2014 2:00PM