Avalanche Forecast

Issued: Feb 25th, 2013 9:51AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Due to limited field observations

Weather Forecast

Tuesday: Trace amounts of new snow / Moderate southwest winds / Freezing level at 800mWednesday: Light snowfall / Moderate southwest winds / Freezing level at 800mThursday: Heavy snowfall /  Moderate south winds / Freezing level at 1100m

Avalanche Summary

A size 2.5 avalanche was triggered by a party of sledders on Sunday in the Brohm Ridge area, and left a man buried 1.8 metres below the surface. The man was successfully rescued.  Check out the Forecaster blog for the full story.Explosive control produced avalanches to size 2 on Monday. With the current snowpack structure and weather forecast for Thursday, the possibility of triggering large to very large avalanches will continue throughout the week .

Snowpack Summary

Heavy amounts of recent snow and strong winds have created deep and destructive storm slabs. Underneath the new snow, you may find surface hoar that was buried on February 20th. Field reports suggest that it is reactive in many areas throughout the region, particularly at treeline and sheltered alpine terrain where broad shooting cracks have been observed. Where it exists, the buried surface hoar will certainly prolong the reactivity and destructive potential of the newly developed slab. The mid and lower snowpack layers are generally strong and well settled.The current weather will likely be forming new cornices. Expect cornices to be large and unstable.Total snow depths vary from around 400 cm in the south to around 180 cm in the north.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall and strong winds on Sunday have added to ongoing storm/ wind slab instabilities. Triggering will most likely occur in wind-loaded terrain or in areas where buried weak surface hoar exists.
The new snow will require several days to settle and stabilize.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 5

Valid until: Feb 26th, 2013 2:00PM