Avalanche Forecast

Issued: Jan 25th, 2013 9:54AM

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

Avalanche Canada slemieux, Avalanche Canada

Summary

Confidence

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

Weather Forecast

Friday night and Saturday: A bit of a precipitation break with moderate winds with strong gusts from the NW friday night. Another unsettled air mass will bring more precipitation on the region on Saturday but no significant amounts. Light W winds gusting moderate in the afternoon and surface freezing level and seasonal temperatures in the alpine (-5 to -10 C). Sunday: Similar pattern with possibly more precipitation, moderate W winds, cooler temperatures (down to -12 C). Monday: Arctic front tracking towards the region bringing more light to moderate precipitations and even cooler temperatures.

Avalanche Summary

A few natural slab avalanches were reported size 2 on E-NE aspects in the storm snow. A few small slabs were also triggered by skiers on the early January surface hoar found under 60-70 cm below treeline on a North facing aspect.

Snowpack Summary

From 15 to 30 cm of snow fell with the last 2 systems with light to moderate S-SW winds in the alpine and with relatively warm temperatures at low elevations.  Storm slabs are found at all elevations. In the alpine, it is expected that the bond between these slabs and the underlying surface will improve, however they are gaining propagation potential with the continuing settlement. In other words, they could become harder to trigger, but if triggered, they will generate bigger avalanches. The new snow is also sitting on a couple of weak layers; a suncrust on S facing slopes and on a surface hoar layer mostly found below treeline. The bond of the new snow with these layer is now weak and it usually takes longer to improve and is harder to predict. It is therefore important to keep monitoring their location and reactivity to ski and snowpack tests. The early January surface hoar layer down 70-90 cm, also in the below treeline band, is becoming less of a concern to professionals but has recently been reactive to skier traffic in the South part of the region (see avalanche summary section). 

Problems

Storm Slabs

An icon showing Storm Slabs
Expect to find soft wind slabs on lee ridges of W-SW winds in the alpine and treeline. Storm slabs are also present in sheltered areas at treeline and on all aspects below treeline.
Choose well supported terrain without convexities.>Avoid areas where sluffing may have severe consequences.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Persistent Slabs

An icon showing Persistent Slabs
Early January surface hoar layer is patchy but has been more reactive below treeline, especially logging cut blocks.
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

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