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.
South winds have formed wind slabs that rest on a widespread crust. The best riding and highest danger are expected to overlap on high elevation north facing features. Even a brief appearance of the sun may initiate loose wet activity too.
Confidence
Moderate -
Weather Forecast
A low pressure centre over the Gulf of Alaska continues to produce weak systems that impact the Northwest Coast. The Tuesday Night system should deliver another round of snow to the alpine, but it is difficult to pin down accurate snowfall amounts at this time, stay tuned for more details.MONDAY NIGHT: Freezing level around 1300 m, light to moderate southwest wind, trace of snow possible.TUESDAY: Overcast, freezing level around 1000 m, moderate west/southwest wind, 1 to 5 cm of snow possible. Another 5 to 10 cm of snow possible on Tuesday Night.WEDNESDAY: Broken cloud cover, freezing level rising to around 1000 m, light southwest wind, 1 to 5 cm of snow.THURSDAY: A few clouds in the morning with potential for clear skies in the afternoon, freezing level climbing to 1500 m, light variable wind, no significant snowfall expected.
Avalanche Summary
We received a great MIN report from the Shames backcountry that describes an active wet loose avalanche cycle to size 1.5, more details here. Wind slab avalanches were susceptible to explosive triggering on Sunday to size 2.5 as well. If you're out we'd love it if you would submit what you're seeing to the Mountain Information Network.
Snowpack Summary
10 to 40 cm of rather wet storm snow now rests on a weak layer buried April 4th which consists of crust, surface hoar and facets. The crust is widespread and up to 4 cm thick. Spotty surface hoar and facets have been reported on top of the crust on high elevation north facing slopes. Moderate to strong wind generally out of the south over the weekend likely formed fresh slabs which may remain sensitive to human triggering. North facing alpine terrain also has a layer of facets down 40 to 100 cm below the surface, but this layer has not been recently active and is likely trending towards dormancy.Below treeline the snowpack is isothermal throughout much of the forecast region.
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 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.