Avalanche Forecast

Strong and gusty southwest winds are expected on Monday. This will be a change to relatively calm winds over the past several days. Plenty of recent, undisturbed snow is available for transport, especially in the northern portion of the West-Central zone. Existing slabs will thicken and fresh slabs will form in leeward terrain at mid and upper elevations. Lingering storm slabs may still be possible to trigger in areas unaffected by wind. Be especially cautious on convex upper elevation slopes steeper than 35 degrees - terrain characteristics where nearly all recent avalanches have occurred. Continue to check how the recent snow is bonding to the old snow surface buried about one foot deep. Expect to encounter the most reactive slabs in leeward areas just below ridges and in cross loaded gullies. Watch for blowing snow, fresh cornice formation, and pay attention to subtle changes in the surface snow. Stiffer slabs, textured surfaces, and lens-shaped pillows are good indications that you have found wind slabs. If you experience shooting cracks, collapses, or see recent avalanches, seek out well-supported, lower-angled terrain.

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.

Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..

Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.

Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.

Expect sunshine and warm temperatures to continue on Monday morning before skies cloud over. The majority of wet loose activity may have already run its course, but continue to watch for roller balls and pinwheels as signs that loose avalanches may follow. They have the potential to entrain quite a bit of snow. Avoid steep, rocky, sun-exposed slopes during the warmest hours of the day. Even though these avalanches would likely be small, they could have serious consequences around terrain traps like gullies or cliff bands.

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. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. 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.

Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.

Several loose wet avalanches, and lots of pinwheels and roller balls.

Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.