Regions
Northwest Coastal.
Confidence
Fair - Intensity of incoming weather is uncertain
Weather Forecast
An approaching Pacific low will mix up the recent weather pattern starting Thursday evening. Overnight Thursday: Snow amounts 10-15 cm. Ridgetop winds moderate gusting strong from the SE. Freezing levels 1000 m. Friday: Snow amounts 10-20 cm. Ridgetop winds moderate-strong from the SW. Freezing levels 1200 m by the afternoon. Saturday/Sunday: A ridge will persist on Saturday bringing dry conditions and sunshine. Sunday will see dry and mild conditions with increasing high cloud. Freezing levels through the weekend will hover around 1500 m.
Avalanche Summary
Reports od natural glide activity continued through the Skeena corridor. Loose wet avalanches up to size 1.5 continue on steep solar aspects. Explosive testing done within concerning glide slabs produced 2 size 1-2 releases. On Tuesday a large explosive control mission reported 10 size 2-2.5, and 1 size 3 avalanches. Slopes targeted were E-SE, 1500 m and below.
Snowpack Summary
Forecast new snow and wind may build wind slabs on lee slopes, and behind terrain features. Recent spring-like conditions exist through the region. Melt and frozen surfaces continue on all aspects. Slopes that start to become wet, and slushy should be avoided because loose wet avalanches may occur. Lately, a lack of consistent overnight freezing has left the snowpack weak and unconsolidated, even isothermal below 1100 m, although some re-freezing has been reported in some areas. Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. Large cornices loom, and ice cliffs pose a threat from above. For more information on Spring Conditions and ways to mitigate risk, please visit the new Forecasters Blog Post.
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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.