Avalanche Forecast

Issued: Apr 5th, 2015 9:17AM

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

ghelgeson, Avalanche Canada

South Columbia.

Warmth remains the primary driver of avalanche hazard as we shift into a more spring like pattern. Minimize your exposure to large slopes if the snowpack is becoming moist or wet.

Summary

Confidence

Fair

Weather Forecast

MONDAY: Freezing level starting at valley bottom, rising to 1600m. Light variable winds at all elevations. No significant precipitation expected. Broken cloud cover.TUESDAY: Freezing level starting at 700m, rising to 1800m. Light variable winds at all elevations. No significant precipitation expected. Skies clearing in the afternoon.WEDNESDAY: Freezing level starting at 1000m, rising to 2000m. Light N/NE winds at all elevations. No significant precipitation expected. Clear skies.

Avalanche Summary

On Saturday storm slabs ran to size 1.5 on NE through NW facing features between 1900 and 2700m. Loose dry avalanches to size 1.5 were reported from all aspects between 2000 and 2500m. A few size wet slabs were reported from southerly facing features between 2100 and 2500m. There were a couple noteworthy avalanches from last week. On Thursday a rider was partially buried in a size 2.5 wind slab on a north aspect at 2600m. On Wednesday, a naturally-triggered size 2.5 wind slab was observed on a NE aspect at 2500m. On that same day an ice fall triggered a size 3 deep persistent slab which failed at ground.

Snowpack Summary

Up to 20cm of dry snow may be hiding previously formed wind slabs on upper elevation slopes. These overlie a crust which varies in thickness with elevation. Sun may destabilize new snow and cornices. Below about 2000 m, loose moist snow makes up much of the snowpack underneath a surface crust. Persistent weak layers in the upper snowpack remain a lingering concern. The mid-March crust/facet layer is down around 60 cm. Down around 80 cm is the mid-February crust/facet/surface hoar layer. Both of these layers are slowly improving in strength, although it may still be possible to trigger one of these, causing a very large avalanche.

Problems

Loose Wet

Continued sun will likely drive ongoing loose wet activity.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

Wind slabs may be found behind terrain breaks like ridges and ribs. Large cornices may be fragile - give these a respectful berth.

Give cornices a wide berth when travelling on or below ridges.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

Buried persistent weak layers may still be reactive to human-triggering. Most likely triggers include a person or machine on a thin snowpack spot, or a cornice fall.

Caution around convexities or areas with a thin or variable snowpack.>Dig down to find and test weak layers before committing to a big line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Apr 6th, 2015 2:00PM