Avalanche Forecast

Archived

Apr 10th, 2018–Apr 11th, 2018

Alpine

Natural avalanches possible, human triggered probable.

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, 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, human triggered possible.

Regions

Northwest Coastal.

New snow and strong winds will form storm slabs at upper elevations, while lower elevations are likely to receive rain. Be aware of conditions that change with elevation as you transition from wet to new snow.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

TONIGHT: Flurries. Accumulation 10-15 cm. Ridge wind strong to extreme, south. Alpine temperature near -2. Freezing level lowering to 800 m.WEDNESDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind strong to extreme, southeast. Alpine temperature near -2. Freezing level 1200 m. Snow beginning in the evening.THURSDAY: Mix of sun and cloud, flurries ending. Accumulation 5-10 cm. Ridge wind moderate, south. Alpine temperature near -5. Freezing level 1100 m.FRIDAY: Mostly cloudy, snow. Accumulation 10-20 cm. Ridge wind moderate, south. Alpine temperature near -5. Freezing level 1100 m.

Avalanche Summary

Northern parts of the region reported that; warming on Sunday and Monday produced a natural, loose, wet avalanche cycle up to size 2 on all aspects up treeline and in steep alpine terrain. Last week, the Shames area saw a widespread natural cycle up to size 3 on solar aspects as a result of Friday's storm. See recent MIN report. While further north only isolated wind slab and loose, wet activity was reported. Read MIN report.On Thursday northern parts of the region saw a widespread natural avalanche cycle triggered by strong to extreme wind loading event in the alpine. There was also a report of an icefall triggered size 2.5 slab avalanche that failed on the mid-March interface, northwest of Meziadin Lake.

Snowpack Summary

Rain and warming to ridge top elevations have created wet or moist snow in the top 20-30 cm of the snowpack that is likely to be covered by a light dusting of new snow by Wednesday morning. Only high alpine, north aspects (above 2000 m) may still be harboring dry snow. In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

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.