Avalanche Forecast

Archived

Apr 15th, 2021–Apr 16th, 2021

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 as the avalanche hazard and temperatures continue to rise.

Weather Forecast

A "Rex-Blocker" ridge of high pressure is anchored over Rogers Pass, bringing with it clear skies, light wind, and warm/inverted temperatures. Expect these conditions to amplify over the next few days, and continue until Sunday evening. Today the FL is forecast to reach 2800m, and drop down to 1600m tonight. Friday and Saturday will be the hottest.

Snowpack Summary

Spring melt-freeze conditions exist at lower elevations, and higher on solar aspects. Polar aspects are still holding dry snow in the alpine and at treeline. The April 7th layer is down ~20-40cm depending on aspect and elevation, and the March 18th crust is down ~60-1m. The mid and lower snowpack is very strong and dense.

Avalanche Summary

Natural avalanche activity will increase in the next few days as temperatures continue to rise, with no significant overnight refreeze. A skier accidental size 2 occurred in the Forever Young couloir on Monday, see the MIN report here. On Sunday a large cornice was accidentally triggered by a skier on the Young's Pk approach.

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.