Avalanche Forecast
Regions: Cascades - South East.
Any isolated wind slabs will continue to gain strength Saturday. Watch for wet snow conditions at lower elevations. There is an increased hazard from an uncontrolled fall on steep slopes with a smooth surface crust.
Detailed Forecast
Light winds and a few light snow showers should continue to decrease the current avalanche danger. Any recent wind and storm slabs should continue to slowly settle and stabilize.Â
Watch for any wet snow conditions at lower elevations, especially on steep unsupported terrain features.
Continue to be cautious Saturday in steep, recently wind loaded terrain, mainly below ridges above treeline.Â
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Snowpack Discussion
Weather and Snowpack
High pressure Saturday to Tuesday brought increasing sunshine and warming temperatures. Temperatures reached the 30's and 40's in many areas along the Cascade east slopes. This caused snowpack settlement, some small loose wet avalanche activity and left a melt-freeze crust in many areas.
Yet another atmospheric river arrived across the PNW beginning on Wednesday.  Light to moderate snow with warmer temperatures and some high snow levels occurred along the east slopes of the Cascades with localized freezing rain along the lower east slopes. Above freezing temperatures occurred during precipitation with light rain likely in the southeast zone up to 7000 feet, 5000-6000 feet in the central-east and reports from the north-east zone of a thin freezing-rain crust to near treeline elevations at least.Â
Recent Observations
North
NWAC observer Jeff Ward was out Thursday, 2/16 and reported about 10 inches moist storm snow was being transported and building wind slabs through the day. There was evidence of a few natural wind slab releases and a natural storm slab was noted releasing sometime Thursday. A thin freezing rain crust formed mid-storm cycle and was yet to form a good bond as of Thursday.
More reports Friday near Washington Pass showed moderate snowpack test results at the interface of the storm snow and melt-freeze crust, down about 14 inches. Yet not triggered slides occurred in steep terrain, including steep convexities. Snowmobiles were highmarking in the Washington Pass area Friday with no triggered slides, showing good stabilization in the recent storm snow. Â
Central
NWAC's Tom Curtis travelled in the Icicle Creek area near Cashmere Mountain Saturday 2/11. Tom did not get far as there was only a dusting of recent snow over a slick, firm crust. The greatest danger in this area was from uncontrolled falls on the slick crust as opposed to avalanches.Â
Another report via the NWAC Observations page for Dirty Face Peak for Sunday indicates that wind slab was unreactive there on Sunday.
Thursday afternoon 2/16, warm temperatures had reached the lower east slopes and numerous wet snow avalanches had released, including in Tumwater Canyon.
Reports from the Mission Ridge pro-patrol Friday indicated that the previous wet snowpack had locked up and formed a strong surface crust in most terrain with little to no new snow above.
South
No recent observations.Â
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: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood: Unlikely
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.
Elevations: Below Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1