Avalanche Forecast
Regions: Olympics.
Wet snow avalanches near and below treeline will be the primary concerns Friday. Be wary of increasing sign of surface snow instability and avoid terrain traps where even a small but heavy wet snow avalanche could be dangerous.
Detailed Forecast
Rain and snow showers should taper down overnight and into Friday morning.  There should be some partial clearing in the afternoon. Despite some cooling relative to the last couple of days wet snow avalanches will continue to be the primary concern  Friday, primarily in the below and near treeline zones. Direct sunshine especially on solar aspects should help accelerate this process, so use increasing caution in the late morning and afternoon hours.Â
Steep slopes that recently received heavy snowfall should be primed for wet loose avalanches. Natural pinwheeling of surface snow is usually a precursor to this type of avalanche. Expect wet loose avalanches to potentially entrain the most recent storm snow and become potentially large and dangerous.  If you are sinking in more than ankle deep, expect wet loose avalanches to be possible on steeper slopes.
Wet slab avalanches are possible if the saturated slab above is poorly bonded to the early March crust and this could allow for a much larger slide on all aspects. Wet slab avalanches are harder to predict than wet loose releases and may not be tied to direct sunshine or the warmest temperatures.  This will not be listed as a concern because of the low predictability. In the same vein cornices are expected to still be sensitive on Friday. Â
Storm slab will also be listed as a concern near and above treeline on all aspects although expect the most loading on lee aspects. Wetter denser new snow accumulating over lower density snow in the above treeline zone will contribute to this concern.
Snowpack Discussion
Recent Weather
A very active two week storm cycle ended 2/25. This cycle produced about 9 feet of snowfall and produced many avalanches near the Hurricane Ridge area.
Warm dry weather was seen late last week Wednesday to Saturday causing wet snow avalanches and melt/freeze crusts at Hurricane Ridge and throughout the region.Â
A series of storms began Sunday March 2nd and have been moving through daily over the past five days. There has been about 3.5 inches of water and 1-2 feet of new snow deposited at Hurricane Ridge during this period as the snow level has reached 6000 feet at times.  Â
Hurricane Ridge
Last Saturday, a NPS ranger and observer Tyler Reid reported a very hard surface crust had formed as a result of the significantly colder overnight and early morning temperatures.
The latest storm cycle that began on Sunday likely produced an avalanche cycle at Hurricane Ridge similar to the Cascades Sunday night and Monday morning. Â Though no first hand observations have been made, poor bonds to the melt-freeze crust from late last week will likely have provided bed surfaces and weak layers for storm slab failures.
Snow levels have been rising and temperatures warming with increasing instability and avalanches similar to the Cascades on Tuesday afternoon and again Wednesday however we are still in the dark, so to speak, with no observations from the Hurricane Ridge area or anywhere else in the Olympics.
On Thursday heavy rain and snow continued, likely causing additional wet snow avalanches near and below treeline. A couple of inches of wet snow were recorded through 4 PM Thursday at the NWAC site.Â
The mid and base pack around Hurricane Ridge should still consist of stable crusts and melt form layers from periods of warm weather earlier this winter. Also in the below tree-line zone on solar aspects rain and mild temperatures may keep the shallow snowpack wet and unconsolidated.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.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 1
Storm Slabs
Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-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.
You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.
Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1