Avalanche Forecast

Archived

Apr 11th, 2019–Apr 12th, 2019

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Regions

Glacier.

All of the Winter Restricted Areas are closed today. Avalanche control with artillery fire and Remote Avalanche Control Systems is scheduled throughout the day.

Weather Forecast

Fog patches dissipating this morning; freezing levels rising from 800m to 1600m this afternoon, and a mix of sun and cloud with isolated flurries for the rest of the day. Winds should be light to moderate from the West. A dirty ridge of High-Pressure will pass over Rogers Pass on Friday, followed by showers and flurries for Saturday.

Snowpack Summary

In the alpine, Isolated persistent slabs overlie surface hoar on shaded aspects, and melt-freeze crusts on solar aspects; beneath is a well settled mid and lower snowpack. A weak melt freeze crust is capping isothermal snow on all aspects to tree line; surface crusts exist at higher elevations on solar aspects.

Avalanche Summary

Avalanche activity tapered off yesterday with the lack of solar input. Numerous loose and slab avalanches to size 2.5 have been observed in the alpine on all aspects on Monday and Tuesday; including Video, Cheops, 8812, Grizzly, Catamount, Bagheera, up the Asulkan and Ille valleys. There is a MIN of a sz 2 slab avalanche on Mt Leda from Tuesday

Confidence

Problems

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.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.