Avalanche Forecast

Archived

Mar 6th, 2024–Mar 7th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Regions

Sea To Sky, Brandywine, Homathko, Spearhead.

Dangerous conditions persist. Manage the uncertainty around buried weak layers by sticking to low-angle terrain, avoiding overhead hazard, and communicating with groups around you.

Confidence

Moderate

Avalanche Summary

Active avalanche conditions continue!

Monday, natural avalanches to size 2 were observed on north and west facing slopes at treeline with crowns up to 1 m. Reports included more evidence of the natural cycle to size 3, likely due to sun.

On Tuesday, several observers noted a new size 2.5 slab release from Cowboy Ridge, although details of the occurrence are limited.

MIN users continue to report remotely triggered avalanches. Check out the many recent MINs from this week!

Snowpack Summary

A thin melt-freeze crust likely exists on solar aspects as a result of Tuesday's sunshine. Where crust formation hasn't inhibited wind transport, elevated winds, recently northerly, have been redistributing surface snow.

Under the evolving surface, 120 -160 cm of progressively resistant or 'right side up' storm snow is continuing to settle above the problematic crust/facet/surface hoar layer beneath it. This layer continues to show sensitivity to human triggers, and is most concerning at treeline elevations where weak grains like facets and surface hoar are more easily preserved.

Weather Summary

Wednesday night

Partly cloudy. 5 - 15 km/h northwest alpine winds. Freezing level at valley bottom.

Thursday

Partly sunny with increasing cloud and flurries beginning overnight. 10 - 25 km/h southwest alpine winds. Treeline temperature -6 °C with freezing level around 900 m.

Friday

Cloudy with increasing snowfall bringing 20-30 cm of new snow, including overnight amounts. 50 - 70 km/h south alpine winds. Treeline temperature -2 °C with freezing level around 1200 m.

Saturday

Cloudy with continuing heavy snowfall bringing 15-20 cm of new snow and 2-day totals to 60 - 90 cm. 40 - 100 km south alpine winds, easing. Treeline temperature -4 °C with freezing level around 1100 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Remote triggering is a concern, watch out for adjacent and overhead slopes.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

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.

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.