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

Jan 18th, 2020–Jan 19th, 2020

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

Regions

South Coast.

A mix of heavy snowfall, strong wind, and a transition to rain are expected to maintain a widespread natural avalanche cycle in the region on Sunday. Travel in avalanche terrain is not recommended.

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Saturday night: Cloudy with continuing snowfall bringing 30-40 cm of new snow. Moderate to strong south winds.

Sunday: Cloudy with easing snowfall bringing 10-15 cm of new snow before transitioning to light rain. Moderate to strong south winds. Alpine temperatures increasing to +3 as freezing levels climb to 2200 metres by afternoon.

Monday: Cloudy with wet flurries or rain bringing about 10 cm of new snow to the alpine. Moderate south winds easing over the day. Alpine temperatures around 0 to -1 with freezing levels to 1500 metres.

Tuesday: Cloudy with wet flurries bringing about 10 cm of new snow to alpine and treeline. Moderate south winds. Alpine temperatures around -2 with freezing levels dropping from 1400 metres to 1000 metres over the day.

Avalanche Summary

No avalanches from the current storm have yet been reported, but the ongoing storm has been forming a widespread new storm slab problem as new snow accumulates and forms slabs as a result of wind and rising temperatures. Active natural avalanche conditions are expected to have become increasingly widespread in areas that saw upwards of 25 cm of new snow by the end of the day Saturday.

A further rise in temperatures may allow for rain falling on snow late Sunday, which will further destabilize recent snow accumulations and promote wet loose avalanche activity.

Snowpack Summary

2-day snow totals over the region are expected to reach 50-60 cm by the end of the day on Sunday. The new snow has buried wind-affected surfaces in exposed areas at all elevations and soft, low density snow in sheltered areas.

The new snow will bring snow totals from the past week to about 170 cm. Collectively, all this snow rests on a hard melt hard melt-freeze crust below 1500 m and on previously wind-affected snow at higher elevations.

In some areas a weak layer of surface hoar exists above this crust. Recent snowpack tests on the North Shore have given variable, sometimes quite sudden results at this interface, particularly where this combination of crust and surface hoar was identified.

Terrain and Travel

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

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.