Avalanche Forecast
Regions: Cascades - South East.
Expect fresh wind slab size and sensitivity to vary considerably near and above treeline Thursday but to generally be found on westerly aspects. Small potential winds slabs will likely be found on steeper wind loaded slopes above treeline. Small loose wet avalanches are possible on steep solar slopes - be wary of them around terrain traps.
Detailed Forecast
Continued sunny and mild weather is expected Thursday with an inversion present. SE winds on Thursday should decrease in the passes as the day progresses, limiting further snow transport.
Above treeline terrain is where enough recent generally settling snow exists for wind to transport snow and form wind slab. These slabs should be found more commonly on west-facing aspects and older wind slabs are becoming increasingly stubborn, while newer, fresher wind slabs may be more reactive. Watch for areas of wind-scoured slopes which transport snow onto lee features and avoid the latter. These slabs will generally be small due to the limited amount of snow available for transport.
As warming continues to occur tomorrow, particularly at higher elevations, watch out for loose wet avalanches forming on solar aspects. These are generally expected to be small, but where deeper snowpacks exist, backcountry travelers should take note about the potential for something larger. Lack of observations from this region will require assessment of conditions from the backcountry traveler. Continue to watch for small, loose wet avalanches on steep sun becoming widespread on steep solar aspects during the late morning or afternoon, especially on unsupported slopes or near rocks.
Early season terrain hazards still exist, such as poorly covered rocks, vegetation and creeks, particularly at lower elevations and exposure to these hazards increases the danger of any avalanche.
Snowpack Discussion
Warm, wet weather before Thanksgiving caused first storm, then wet snow avalanches in the Washington Pass area.  Post-Thanksgiving about 2 feet of snow accumulated in the Washington Pass area and this amount has settled above the Thanksgiving Day crust.
A series of frontal systems produced snow over the week following Thanksgiving at all stations in the Cascades: Locations on the east side of the Cascade crest have received 5-15".
The most recent snowfall ended early Sunday.Â
Dry and cool conditions Sunday through Wednesday under a high pressure system have allowed for up to five inches of snowpack settlement and allowed recent storm layers to begin stabilizing. Warm and sunny weather Tuesday and Wednesday at higher elevations, particularly, allowed for further consolidation and some moist surface snow on solar aspects.  An inversion was firmly established on Wednesday, with much cooler temperatures present at Washington Pass base (not making it out of the mid-20's) than the upper Washington Pass site which topped out in the low 40's. Winds were generally light on Wednesday in the NE Cascades with winds affecting the snow more significantly in the lower-elevation gaps in the terrain in the central cascades.
Observations
North
No observations.
Central and South
On Saturday, backcountry professionals skiing at Ingalls Peak reported generally stable conditions with some small, unreactive wind slab.
Avalanche Problems
Wind Slabs
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.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 1
Loose Wet
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.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1