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

Jan 19th, 2016–Jan 20th, 2016

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

Regions

Olympics.

Previous wind slab is the most likely problem on Wednesday. Evaluate the snowpack carefully and identify terrain features of concern such as convex rollovers and slopes that may have received recent wind deposited snow. 

Detailed Forecast

Light snow showers should end at Hurricane by Wednesday morning. A short relative break may be seen at Hurricane Wednesday afternoon.

New wind slab is unlikely due to limited amounts of new snow at Hurricane. Older wind slab is most likely on lee north to southeast slopes near and above treeline.

New storm slab is also unlikely due to limited amounts of new snow at Hurricane. But watch for small areas of shallow wind slab if you find there has been more than a few inches of new snowfall.

Also here is a heads up that a strong wet warm front is headed our way for Thursday.

Snowpack Discussion

Deep storm snow that fell during mid-late December is well settled, homogeneous and has stabilized so the current avalanche danger should be confined to the uppermost recent storm snow.

The latest period of snowfall should have deposited about 1.5 feet of snow at Hurricane from about Friday to Sunday with fluctuating snow levels and periods of strong, mostly S-SW winds.

A fairly vigorous surface low pressure and frontal system will cross the south Cascades Tuesday and Tuesday night. This should bring heavy snow to the south Washington Cascades, moderate snow to the central Cascades and lighter amounts of snow to the Olympics and north Cascades. A minor drop in snow levels should be seen following this system except for a bump in snow levels in the passes when winds change to west there Tuesday night.

Problems

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.

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.