Avalanche Forecast

Issued: Jan 4th, 2016 8:33AM

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.

jlammers, Avalanche Canada

Northwest Coastal.

You don't have to be an avalanche expert to submit to the MIN. If you've been in the mountains, the backcountry community would love to know what you observed!

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

Expect a mix of sun and cloud for the forecast period with a chance of very light flurries on Wednesday and Thursday. Ridgetop winds are expected to be moderate to strong from the southeast on Tuesday and Wednesday, becoming light by Thursday. Freezing levels are expected to remain at valley bottom for the forecast period.

Avalanche Summary

On Sunday, a few avalanches were reported from the north of the region: A skier accidentally triggered a size 1.5 wind slab avalanche which failed on the December 26 surface hoar layer at about 1450m on an east aspect. A few other size 1.5 explosive-triggered wind slabs were also observed in north-facing alpine terrain.

Snowpack Summary

Snowpack surfaces are highly variable. Temperature inversions and solar radiation have recently come into play and a melt-freeze crust can be found on steep, solar aspects in the alpine. On most other slopes, 25-40 cm of snow from the Boxing Day storm continues to settle and facet, and new surface hoar has been reported although its distribution is likely variable due to strong outflow winds. In areas where recent winds have been light, shaded slopes will likely provide settled powder. In areas where winds have been stronger, reactive wind slabs may exist, especially in areas where the the slab overlies surface hoar buried by the Boxing Day storm.Professionals in the region are still keeping an eye on a few other surface hoar layers that developed throughout December which are now buried in the top 100cm. Although these layers may be gaining strength, they are worth keeping an eye on, especially on steep unsupported slopes at treeline and below. In colder and shallower snowpack areas watch for weak basal facets.

Problems

Wind Slabs

Be on the look-out for new wind slabs formed by strong outflow winds on Monday. Older wind slabs may be surprisingly deep in areas where they overlie surface hoar buried at the end of December.

Be cautious as you transition into wind affected terrain.>Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>Avoid travelling in areas that have been reverse loaded by winds.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

A few surface hoar layers buried in mid December are becoming unlikely to trigger; however, some snowpack tests are still showing sudden results. Use extra caution on steep, unsupported slopes at treeline and below.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>Use caution on 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 - 3

Valid until: Jan 5th, 2016 2:00PM