Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 22nd, 2017–Dec 23rd, 2017

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 possible, human triggered probable.
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.

Regions

South Coast Inland.

Hazard ratings are for the southern part of the region where storm snow totals range from 80-100 cm. Northern areas that received lower snowfall amounts can expect the same avalanche problems with lower hazard ratings.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

SATURDAY: Sunny. Ridge wind light from the northeast. Temperature -10. Freezing level surface.SUNDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind light from the southeast. Temperature -12. Freezing level surface. Strong outflow winds near coastal valleys.MONDAY: Mix of sun and cloud. Ridge wind light from the northwest. Temperature -10. Freezing level surface.

Avalanche Summary

There were no new reports of avalanches on Thursday although whumpfing in hard wind slabs on cross-loaded features at treeline was observed in the northern part of the region. On Wednesday the Coquihalla and Allison Pass areas saw numerous loose dry to Size 1.5, as well as slab and glide avalanches to Size 2 on steep, leeward terrain and smooth rock slabs. Reports from the northern part of the region indicated wind slab activity up to size 2 on north and west aspects in the alpine.In the southern part of the region classic signs of instability such as whumpfing and shooting cracks have also been reported here in the MIN.

Snowpack Summary

The recent storm snow has been redistributed by moderate to strong northerly winds in the alpine and exposed treeline areas, creating wind slabs in some areas and scouring others (particularly in the northern part of the region).The southern part of the region has seen impressive storm snow totals (80-100cm) since Sunday night, compared to northern areas of the region, which received 25-35cm. This new snow sits on crusts of variable thickness that formed on almost all aspects in mid-December (December 15th layer). On steep southerly aspects the crust is supportive, whereas on northerly aspects the crust is quite thin and variable. Beneath the December 15th layer the snowpack is well settled. The late November rain crust is now buried 50-80 cm in the northern part of the region and well over 1 m in the south.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.