Avalanche Forecast

Archived

Apr 17th, 2025–Apr 18th, 2025

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

Glacier.

Solar warming is intensified this time of year.

Get up and complete your mission early before the heat of the day destabilizes the snowpack.

High elevation, N-facing slopes hold dry snow and a "sneaky" surface hoar problem. Watch for slabs up there.

Confidence

Moderate

Avalanche Summary

Few natural avalanches have been observed on the highway corridor over the past 4 days.

Neighboring operations are reporting small wet loose avalanches on solar facing terrain and natural cornice falls.

On Apr 14, a party observed several sz 2 wet/loose avalanches from steep, S-facing terrain on Mt Green.

On Apr 11, a skier triggered sz 2 wind slab on the Dome glacier at 2450 m, NE asp.

Also on Apr 11, a wide-propagating, rider triggered sz 2.5 on Bruins Glacier.

Snowpack Summary

Daily melt/freeze cycles are affecting the surface of the snowpack on solar slopes and all aspects up to 2200m, with several crusts of variable strength in the upper snowpack. High alpine, north facing slopes still hold dry snow. A spotty, buried surface hoar layer exists down 15-40cm in sheltered north alpine areas above ~2300m. This layer has been reactive to human triggering in the past week.

Below treeline, conditions are variable and challenging travel exists.

Weather Summary

A final day of clear skies on Friday and strong solar inputs. Saturday a cold front ushers in flurries/showers.

Tonight Clear. Alp low -2°C. Ridge wind NW 10-25 km/h. Freezing Level (FZL) 1500m

Fri Sun & cloud. Alp high 2°C. Ridge wind SW 15-25 km/h. FZL 2400-2900m

Sat Cloudy/flurries. 5 cm Alp high 0°C. Ridge wind W 20-30km/h. FZL 2200m

Sun Cloudy/flurries 5cm Alp high -2°C. Ridge wind light. FZL 1900m.

Terrain and Travel Advice

A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
Carefully evaluate steep lines for wind slabs.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

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.

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.