Avalanche Forecast

Archived

Apr 14th, 2024–Apr 15th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

Haines Pass.

Choose conservative, low consequence terrain.

Buried weak layers remain rider triggerable.

Confidence

Moderate

Avalanche Summary

Many natural and rider-triggered avalanches released on Thursday on the weak layers described in the Snowpack Summary (see photos below). These weak layers may take some time to strengthen, meaning they will likely remain active to human traffic for the foreseeable future.

Please consider sharing your observations to the Mountain Information Network.

Snowpack Summary

Recent storm snow has been redistributed by southerly winds and has likely formed wind slabs near ridge crest. As the winds switch direction wind effect could be found on all aspects.

The snow surface on sun exposed slopes will likely become moist during the day.

Weak layers of surface hoar crystals and/or faceted grains may be found around 30 to 70 cm deep. This layer has produced recent avalanche activity and is unstable in snowpack tests.

Cornices are large and looming at this time of year.

Weather Summary

Sunday Night

Clearing skies with trace amounts of new snow in the early evening. 20 to 35 km/h north alpine wind. Treeline temperature -12°C.

Monday

Sunny. 15 to 35 km/h northwest alpine wind. Treeline temperature -3°C.

Tuesday

Sunny. 5 to 15 km/h south alpine wind. Treeline temperature -2°C.

Wednesday

A mix of sun and cloud with trace amounts of new snow in the AM. 10 to 25 km/h southeast alpine wind. Treeline temperature -1°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Keep in mind that human triggering potential persists as natural avalanching tapers off.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Avoid sun exposed slopes, especially if snow surface is moist or wet.

Problems

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.

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.