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

Mar 18th, 2020–Mar 19th, 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.
Below Treeline
Natural avalanches unlikely.

Regions

Northwest Coastal.

Loose wet avalanche activity on sun-exposed slopes and cornice falls are expected to continue during the heat of the day. Use caution around sheltered treeline where persistent slabs could be triggered.

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

WEDNESDAY NIGHT: Partly cloudy, light south wind, alpine temperature -1 C, freezing level 1200 m.

THURSDAY: Clear skies, light east wind, apine temperature -1 C, freezing level 1200 m.

FRIDAY: Clear skies, light northwest wind, alpine temperature 0 C, freezing level 1400 m.

SATURDAY: Mix of sun and cloud, moderate to strong northwest wind, alpine temperature -5 C, freezing level 1000 m.

Avalanche Summary

There was evidence of natural loose wet avalanche activity on sun-exposed slopes on Tuesday. A few cornices were also triggered by the warming. This trend is expected to continue with generally sunny skies and relatively warm air temperature.

If you decide to travel in the backcountry, consider sharing your observations with us and fellow recreationists via the Mountain Information Network (MIN) to supplement our data stream as operators are shutting down. Even just a photo of what the day looked like would be helpful.

Snowpack Summary

Wind-affected snow surface exist in exposed terrain at alpine and treeline elevations from predominantly northeast wind. Previously formed wind slabs have likely bonded given the recent warming trend. In sheltered terrain, soft and faceted snow may be found. Clear skies have melted the snow surface on sun-exposed slopes during the day and frozen it into a melt-freeze crust during nights.

A layer of surface hoar crystals is buried around 30 to 60 cm in sheltered areas at and below treeline. See this MIN from the Shames area that shows this layer when it was on the surface, prior to burial on March 9.

An early-season layer of faceted grains and a melt-freeze crust may linger at the base of the snowpack. A large load, such as a cornice fall, has the potential of triggering it.

Terrain and Travel

  • Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
  • Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
  • Be aware of the potential for large avalanches due to the presence of buried surface hoar.
  • Carefully evaluate steep lines for wind slabs.

Problems

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.

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.