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

Feb 29th, 2016–Mar 1st, 2016

Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

Olympics.

Very dangerous avalanche conditions are expected to develop late Monday night and last through Tuesday especially near and above treeline. Travel in avalanche terrain is not recommended Tuesday. 

Detailed Forecast

The avalanche danger will increase rapidly Monday night as warm frontal precipitation spreads over the Olympics and increases during the early morning hours. Snow should turn to rain by Monday morning at Hurricane Ridge.

Storm slab instabilities should develop during intense precipitation periods Monday night and due to the overall warming trend. New wind slab should develop mainly above treeline on NW through E slopes. Loose wet avalanches will become very likely on steeper slopes at elevations that see a switch to rain. Avalanches that begin in the new snow may become larger as they entrain or step down to snowfall received Sunday and Sunday night. A quick switch to rain below treeline Monday night will likely cause an avalanche cycle at lower elevations overnight and limit the size of avalanches below treeline. 

Very dangerous avalanche conditions are expected to develop late Monday night and last through Tuesday especially near and above treeline. Travel in avalanche terrain is not recommended Tuesday. 

Snowpack Discussion

Weather and Snowpack

Springlike weather under high pressure Wednesday and Thursday led to abundant sunshine with temperatures climbing into the 40's. This weather allowed for melt-freeze crust formation and varying amounts of wet surface snow depending on slope aspect during the day. A weak front brought mostly light rain to Hurricane Friday night to Saturday morning.

A strong Pacific frontal system blew through the Olympics mid-morning Sunday. Around 12 inches of snow accumulated through Monday morning at Hurricane Ridge accompanied by a cooling trend. Moderate S-SW transport winds seen Sunday tapered off Sunday night. 

The mid and lower snow pack along the west slopes should generally be a stable mix of crusts and layers of moist and rounded snow crystals.

Recent Observations

NWAC pro-observer Matt Schonwald was at Hurricane Ridge Friday and found mostly consolidated stable snow. N to E slopes had areas of 25-30 cm of wind transported 4F snow well bonded to 1F melt form grains in the upper snow pack. South through west slopes were melted out in some places with shallower dense stable snow in others.

The road to Hurricane Ridge remained closed on Sunday due to the weather. 

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). 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.

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.

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.