Avalanche Forecast

Issued: Feb 22nd, 2019 5:07PM

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

kdevine, Avalanche Canada

Cariboos.

Though avalanche occurrences are becoming less frequent, the possibility of triggering persistent slabs and wind slabs still exists. A cautious approach to backcountry travel is recommended.

Summary

Confidence

High -

Weather Forecast

FRIDAY NIGHT - Cloudy with clear periods and isolated flurries / northeast winds 10-15 km/h / alpine low temperature near -17SATURDAY - A mix of sun and cloud / northeast winds 10-15 km/h / alpine high temperature near -17SUNDAY - Sunny with cloudy periods / northeast winds 10-15 km/h / alpine high temperature near -16MONDAY - A mix of sun and cloud / northeast winds, 10-20 km/h / alpine high temperature near -18

Avalanche Summary

On Thursday, a few natural and human triggered size 1-1.5 avalanches were reported.On Wednesday, there were reports of several human triggered size 1 wind slab avalanches. Check out this MIN report from Wednesday.There were no avalanches reported Sunday through Tuesday.Last Saturday, a persistent slab avalanche was triggered by a skier on a north aspect on a 30 degree slope. Check out the MIN report here. These sorts of avalanches are becoming less frequent, but they are still possible and the consequences are high.

Snowpack Summary

Up to 5 cm of new snow fell on Friday with moderate to strong southwest winds. The new snow sits on top of approximately 10-30 cm of low density snow in some areas, and wind slabs in other areas. Due to previous variable wind directions, wind slabs may be found on all aspects, mainly in the alpine and at treeline. A weak layer that was buried in mid January is now buried anywhere from 30-60 cm. This layer consists of surface hoar (feathery crystals) and facets (sugary snow). The layer also likely consists of a crust on south facing slopes. Avalanche activity on this layer has slowed, but test results, and recent observations of whumphing still indicate that this layer may still be easy for humans to trigger in certain locations. It has been most reactive at treeline and below treeline.The lower snowpack is considered generally strong.

Problems

Persistent Slabs

Approximately 50 cm of snow sits above a persistent weak layer of surface hoar that was buried in mid January. The surface hoar may sit on a crust on south aspects.

Avoid steep, open and/or sparsely treed slopes at and below treeline.Use conservative route selection, choose moderate angled terrain with low consequence.Be aware of the potential for wide propagation.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

Parts of the region have been hit hard by winds, which formed wind slabs in the lee of terrain features on a variety of aspects due to shifting wind directions.

If triggered, wind slabs may step down to deeper layers and result in even larger avalanches.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 23rd, 2019 2:00PM