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

Apr 18th, 2019–Apr 19th, 2019

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.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

South Columbia.

Rain/snow and strong winds may initiate a loose wet avalanche cycle at treeline and form fresh storm slabs reactive to human triggers in the alpine.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

THURSDAY NIGHT: Rain (snow above roughly 2300 m.); 10-20 mm / Strong, southwesterly winds / Alpine low 3 C / Freezing level 2500 m.

FRIDAY: Rain (snow above roughly 2100 m.); 10-15 mm / Strong, southwesterly winds / Alpine high 3 C / Freezing level 2300 m.

SATURDAY: Sunny / Light, northwesterly winds / Alpine high 3 C / Freezing level 2100 m.

SUNDAY: Sunny / Light, northwesterly winds / Alpine high 5 C / Freezing level 2300 m.

Avalanche Summary

On Wednesday, explosive control work near Revelstoke produce numerous loose wet avalanches up to size 1.5. Avalanche activity is expected to increase on Friday with the forecast rain/alpine snow and strong winds.

On Tuesday, two naturally triggered size 1.5 storm slab avalanches 25 cm deep were reported on northwest aspects 2200-2400 m.

Several recent natural slab avalanches up to size 2 have been reported on north and east aspects in the alpine. The suspected weak layer was either a crust or small surface hoar that was down 25-50 cm.

Snowpack Summary

5-10 mm. rain (snow above roughly 1900 m.) on Thursday is adding to the 20-40 cm recent snow which overlies a crust everywhere except high elevation, north facing terrain where preserved surface hoar (weak, feathery crystals) may be present in isolated locations. A similar layer buried in early April is down 40-50 cm. Smaller storm slab avalanches may step down to one of these deeper weak layers.

Below treeline, snow is disappearing rapidly.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.