Avalanche Forecast

Archived

Mar 5th, 2023–Mar 6th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

South Coast, North Shore, Sasquatch, Sky Pilot, Tetrahedron.

Variable winds have created reactive wind slabs on all aspects and could be at elevations lower than expected.

Seek out sheltered terrain for the best riding.

Confidence

Moderate

Avalanche Summary

On Saturday, a natural cornice fall trigged the slope below it. This occurred below treeline and was on a west aspect. The aspect and elevation are fairly atypical but representative of the moderate easterly winds we have been experiencing. Make sure to watch out for wind affect on all aspects and elevations.

Check out Friday's North Shore Snowpack Update for a picture of our atypical snowpack setup.

Snowpack Summary

Easterly winds have started to transport the 100 to 130 cm of snow that fell last week. This snow was mostly dry and cold. Warming temperatures have increased the consolidation of the upper snowpack and may promote slab development. If the sun pokes out, it could do the same since it is starting to pack a punch this time of year.

This recent snow sits on a layer of concern made up of a crust with facets. It appears to be gaining strength, but this is a layer to watch out for.

The mid and lower snowpack is well-settled, strong, and consolidated.

Snowpack depths are over 300 cm.

Weather Summary

Sunday Night

Cloudy with clear periods, trace accumulation, winds southeast 15 to 25 km/h, freezing level to 1200 m.

Monday

A mix of sun and cloud, trace accumulation, winds southeast 25 to 35 km/h, freezing level climbing to 1100 m by end of the day.

Tuesday

Cloudy with possible late-day sunny breaks, 10 cm accumulation, winds southeast 30 km/h gusting to 40, freezing level 500 to 1000 m.

Wednesday

Mostly cloudy, 10 to 15 cm accumulation over the 24-hour period, winds southeast 25 km/h gusting to 40, freezing level to 900 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be carefull around freshly wind loaded features.
Loose avalanches may start small but they can grow and push you into dangerous terrain.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Caution around slopes that are exposed to cornices overhead.
Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.