Avalanche danger can rise quickly with daytime warming and solar radiation. Be aware of changing conditions and overhead hazards.
Confidence
Poor - Due to the number of field observations
Weather Forecast
Saturday: Flurries / Light southerly winds / Freezing levels 1800m.Sunday: Flurries /Light southwesterly winds / Freezing levels 1800-2000m.Monday: Mix of sun and cloud with isolated flurries / Light southwest winds / Freezing Level 1800m.
Avalanche Summary
Expect loose wet avalanches in steep terrain if it is raining or during sunny periods, especially if the sun or rain is affecting fresh snow. Spring squalls may bring locally heavy precipitation and new storm or wind slabs may develop in higher terrain if you see significant new snow accumulation. Cornices collapses have been reported during periods of daytime warming. Occasionally these heavy triggers have caused large deep slab avalanches on the slopes below.
Snowpack Summary
This is a broad summary of conditions is based on limited field data and should be supplemented with local observations to help assess avalanche danger.Over the past week or so the Columbias have seen moderate amounts of new snow mixed with showers or periods of rain below 1600-1800 m. Southerly winds have likely formed pockets of wind slab at higher elevations in lee of ridges and terrain features. The upper snowpack generally consists of layers of moist and/or dry snow mixed with several well bonded crusts. Below 1300-1500 m most areas are likely below threshold for avalanches depending on aspect. The mid-March sun crust/surface hoar layer down 50-80cm and the early-March crust/facet/surface hoar layer down around 80-120cm seem to be inactive. The mid-February crust/facet/surface hoar combo is typically down 150 - 200cm. Human triggered avalanches on this layer are unlikely. Larger triggers such as cornice fall, a smaller avalanche in motion or prolonged warming could wake this layer up, resulting in very large and destructive avalanche.
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.