Avalanche Forecast
Regions: Stevens Pass.
The Bottom Line: The danger of wet loose snow avalanches should be less on Tuesday. But continue to watch for local wet loose avalanches on steep solar aspects.
Detailed Forecast
Clear weather should cause a good refreeze of snow surfaces on Monday night.
Then a minor increase in winds, some high clouds and cooler temperatures should be seen on Tuesday. This should result in less surface snow melting, firmer surface snow and less likelihood of wet loose snow avalanches on Tuesday. Continue to watch for quickly softening surface snow in the late morning through afternoon hours on solar aspects. Natural pin-wheels or sinking in more than ankle deep means it is time to get off that slope and away from steeper solar slopes.
Continue to approach previous lee or wind loaded slopes with caution since isolated wind slab may linger on N thru SE aspects near and above treeline zones.
Snowpack Discussion
The most recent storm cycle to impact the Northwest ended Tuesday. The storm produced about 2 - 4 feet of snow at Hurricane and at most NWAC sites near and west of the crest ending Sunday. The tail end of the storm cycle Sunday afternoon through Tuesday was accompanied by a warming trend that brought rain to mid and low elevations and upside down heavy dense snow and slab layers to high elevations.
The main avalanche activity with this cycle occurred a week ago Sunday, 12 January with large to very large D2 to D3 natural avalanches reported throughout the west slopes with start zones mainly in the near and above tree-line zones on wind loaded aspects. Natural avalanches released within the storm snow with isolated but larger slides up to 5' were produced by local ski patrols with explosives.
Wednesday through today has seen a return to sunshine and mild temperatures. This weather has allowed for snowpack settlement of about 5-14 inches at most NWAC sites near and west of the crest over the past week. Last weeks storm snow is now generally well-bonded. Over higher terrain snow surfaces vary from dense powder on wind and sun sheltered aspects...to chalky wind board on lee slopes...to sun crusts or soft shallow wet snow on solar aspects, depending on time of day.  Due to the low winter sun angle the somewhat supportable rain crust at low and mid elevations on non-solar aspects remains firm during the day.  On a better note, there have been many nice reports of good spring-like corn snow on sun exposed terrain at higher elevations over the past several days.
Recent observations:
Recent natural wet-loose activity on solar aspects above Hurricane Ridge, 18 January by NWAC observer Katy Reid
Wind and sun effects near Panorama Point above Paradise, Mt Rainier, 18 January by NWAC Forecaster Dennis D'Amico
NWAC observer Tom Curtis on Wednesday from Jove Peak at Stevens Pass reported a sudden collapse and a clean shear in a compression test on an east aspect near-treeline.  However, this layer did not propagate in an Extended Column Test but suggests there may still be some lingering but increasingly isolated wind slab on lee slopes, though several days of mild weather may have stabilized this layer.Â
Layers seen by NWAC observer Tom Curtis on 15 January, Jove Peak at 5400 ft
The warm and sunny weather activated solar aspects lwith large wet-loose avalanches reported Tuesday and Wednesday that ran into the below tree-line zone in the Stevens Pass area. Â
Wet loose avalanche that ran across snowmobile tracks in the Smithbrook area near Stevens Pass on Tuesday by NWAC observer Dallas Glass. Also a short video about the wet loose snow avalanches:  https://www.youtube.com/channel/UCXKN3Cu9rnnkukkiUUgjzFQ
For the Olympics and west slopes of the Cascades a generally favorable mid and lower snowpack exists and is expected to consist of crust layers and melt form crystals. The avalanche danger is locally lower at Hurricane Ridge where the snowpack on windward and solar aspects near and below tree-line has less snow and ample terrain anchors.
Cornice/avalanche fatality on Lewis Peak: A climber apparently walked onto a cornice on the summit of Lewis Peak east of Everett about Noon on Saturday, 18 January and was killed in the resulting cornice collapse and triggered avalanche. The name of the climber and details are not yet available. Try to assess as best possible the likelihood of cornices and that you are over solid ground before venturing onto snow covered summits and ridges.
Local non-avalanche hazard Snoqualmie Pass area:  On 13 January a heavy local freezing rain event occurred in the Snoqualmie Pass area above about 4500 feet, covering the surface with about a 2-3 inch hard ice crust.  This crust should break down over time but a fall on a slope on this surface could result in a long and dangerous ride!     Â
Avalanche Problems
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: South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1
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: North, North East, East, South East.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 1 - 1