Avalanche Forecast

Archived

Apr 10th, 2018–Apr 11th, 2018

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

South Coast.

Heavy precipitation is falling as rain below treeline and snow in the alpine. Reactive storm slabs are building at upper elevations and natural loose wet avalanches are occurring at lower elevations. Its a good time to avoid avalanche terrain.

Confidence

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

Weather Forecast

Wednesday: Heavy precipitation near 30 mm. Snow above 1200 m and rain below. Ridgetop wind strong from the southwest and freezing levels near 1200m. Thursday: Cloudy with 5-10 cm. Ridgetop wind strong from the South and freezing levels dropping to 900 m. Friday: Yet another blast of winter up high! Heavy precipitation up to 60 mm with snow above 1500 m and rain below. Ridgetop wind continue to be strong from the South and freezing levels near 1500 m.

Avalanche Summary

We have received very little information on avalanche activity for this region. From the little we have heard, there were no new avalanches to report from Tuesday. Forecast heavy precipitation should mean that the likelihood of triggering avalanches is on the rise.We would very much appreciate it if you spend a moment to submit any observations you have to the Mountain Information Network here, even if it is just a photo. Thanks!

Snowpack Summary

Rain is now falling as snow at upper elevations building reactive storm slabs which sit over a predominant thick crust. It is difficult to predict where and when rain will switch to snow, but expect the transition to happen and by Wednesday and most precipitation will fall as snow above 1200 m.At below treeline elevations, a spring snowpack exists. Rain has saturated and weakened the upper snowpack. Forecast rain will continue this trend. The mid and lower snowpack are strong.

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.