Avalanche Forecast

Issued: Jan 11th, 2015 8:20AM

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

bcorrigan, Avalanche Canada

Northwest Inland.

Flurries on Tuesday with SW winds may produce wind slabs on lee slopes. If more snow than forecast arrives, use caution at treeline and above.

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

An upper level trough will move into the area from the Pacific early Tuesday bringing light precipitation, with perhaps 5 to 10 cm of new snow at upper elevations. A bit of clearing on Wednesday, then more light precip. on Thursday and Friday. Winds from the S-SW.Freezing levels should remain around 500m but may spike to 2000m on Wednedsay.

Avalanche Summary

Reports from yesterday include several natural radiation triggered avalanches on steep solar aspects. No other reports of avalanche activity.

Snowpack Summary

Strong and variable winds have created soft and stiff wind slabs on varying aspects in exposed terrain. Below the recent storm snow is a rain crust at lower elevations and a temperature crust has formed in some locations from the recent temperature inversion. In the mid-pack a surface hoar layer has been reported, although it appears to be spotty in distribution. Near the bottom of the snowpack is a crust facet combo that was buried in mid-November.

Problems

Wind Slabs

Wind loaded lee features remain on the radar for the time being, and a temperature crust is making the riding "interesting" at treeline and above. Watch for newly forming windslabs.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

The buried storm slab should be bonding well with the mild temperatures, but still remains a serious consideration. A small avalanche could trigger this buried dense slab, and produce a large destructive avalanche.

Be cautious as you transition into wind affected terrain.>Use caution around convexities, ridge crests, rock outcroppings and anywhere else with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Jan 12th, 2015 2:00PM