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

Feb 17th, 2020–Feb 18th, 2020

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

Regions

Northwest Coastal.

Be ready to step back from sun exposed slopes in the afternoon. Storm slabs may remain reactive in deep wind loaded pockets in the alpine and where it overlies a weak layer of surface hoar crystals at treeline and below.

Confidence

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

Monday night: Scattered cloud. Light northwest wind. Freezing level valley bottom.

Tuesday: Mix of sun and cloud. Light southwest wind. Freezing level 700 m.

Wednesday: Sunny. Moderate to strong south wind. Freezing level 500 m.

Thursday: Mostly cloudy. Moderate southwest wind. Freezing level 500 m.

Avalanche Summary

Over the weekend, natural storm and wind slab avalanches size 2-2.5 were the story in the alpine. One size 3 was observed over the highway corridor and at least one size 2 storm slab was solar triggered. At treeline, human triggered storm slabs size 1-1.5 have been running on surface hoar 40 cm deep.

Snowpack Summary

40-60 cm of snow from the past week has seen some redistribution in exposed alpine areas, with soft wind slabs forming in immediate lees of ridge crests. At treeline and below, it may sit over patches of surface hoar in wind sheltered areas or crusts on solar aspects.

A thin layer of facets that formed during the January cold snap is now about 120-170 cm below the surface while an early season crust lingers at the base of the snowpack. These layers produced a few large natural avalanches in early February but have recently been unreactive.

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Be alert to conditions that change with elevation and wind exposure.
  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet

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.