Avalanche Forecast

Archived

Jan 8th, 2024–Jan 9th, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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.

Regions

Sea To Sky, Brandywine, Garibaldi, Homathko, Spearhead, Tantalus, Sky Pilot.

Very dangerous avalanche conditions exist at higher elevations where heavy snowfall and extreme winds are building reactive storm slabs. Travel in avalanche terrain is not recommended.

Confidence

Moderate

Avalanche Summary

On Sunday, a few natural, size 2, wind slab avalanches and two skier accidental, size 1.5, wind slab avalanches were reported. Wind slabs were reactive to natural and human triggers in cross-loaded terrain on west aspects in the alpine.

On Saturday, several natural persistent slab avalanches were reported to size 3 in the Whistler backcountry. These avalanches occurred on northerly aspects in the alpine.

Snowpack Summary

By Tuesday morning +20 cm of storm snow blankets the Coast Mountains.

This overlies wind-affected surface and 30 to 50 cm of settling snow. A weak lay of surface hoar overlying a crust is found down 50 to 70 cm. becomes thin and variable above 1900 m.

Another crust from early Dec is down 80-150 cm. A few large avalanches observed in the region on January 6 are suspected to have failed on this layer.

Snowpack depths are 120-230 cm around treeline and decrease rapidly below.

Weather Summary

Monday Night

Cloudy with flurries, 20 to 40 cm of snow. Southwest ridgetop winds 40 to 70 km/h. Treeline temperature -7 °C.

Tuesday

Cloudy with flurries, 10 to 20 cm of snow. Southwest ridgetop winds 30 to 50 km/h. Treeline temperature -8 °C.

Wednesday

Partly cloudy with isolated flurries, trace amounts of snow. Northwest ridgetop winds 10 to 25 km/h. Treeline temperature -12 °C.

Thursday

Partly cloudy with isolated flurries, trace amounts of snow. Southwest ridgetop winds 10 to 40 km/h. Treeline temperatures drop through the day to -16 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
Avoid lingering or regrouping in runout zones.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.