Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 17th, 2015–Mar 18th, 2015

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

Olympics.

Winter returned briefly to the Olympics over the weekend, but the mid March sun's strength can rapidly create locally dangerous conditions on steeper solar slopes, where even a shallow and slow moving avalanche could be powerful and could force you into unintended terrain traps. Also, watch for weakening cornices along ridges during the warmer part of the day.

Detailed Forecast

A weak weather system should cause a few showers overnight Tuesday and early Wednesday, but only very light amounts of rain or snow are expected and this should not cause an increased danger. Gradual clearing later Wednesday and some sunshone should lead to warming and increase the chance of small loose-wet avalanches. 

Lighter snow accumulations along with ample terrain anchors should greatly limit the avalanche danger below treeline. 

Due to the low snowpack, especially below treeline, watch for terrain hazards such as open creeks, partially covered rocks and vegetation. Many areas below treeline do not have enough snow to cause an avalanche danger.

Snowpack Discussion

The Olympics had very little snow until this weekend when a warm wet storm Saturday was followed by a strong but cooler storm Sunday for a one-two punch to the Pacific Northwest. Saturday's event brought mostly rain with a few inches of new snow by Sunday morning, followed by heavier snow depositing total storm snow amounts of about 16-18 inches at the Hurricane Ridge snow plot. 

Observer Tyler Reid toured above Hurricane Ridge on Tuesday and reported about 1-2 feet of wet snow with up to 3 feet in wind drifts near ridgeline. There were numerous recent small loose wet avalanches seen on all aspects with a few larger slides.

Evidence seen Tuesday, March 17th, of size 2 loose wet slide debris above tunnels on road to Hurricane Ridge. Photo, Tyler Reid

Since many areas are starting from scratch, smooth slopes without terrain anchors or the slopes with the previous snow cover are the most likely to produce avalanches and most likely found near and above treeline in the Olympics.

Problems

Loose Wet

Loose Wet avalanches are the 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. 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.

Wind Slabs

Wind Slab avalanches are the 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.