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

Nov 26th, 2016–Nov 27th, 2016

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

Regions

.

Watch for wind and storm slab layers on Sunday that may be left over from Saturday especially in the Mt Baker area. Be prepared to ratchet back your plans if conditions get stormy again before the end of the daylight hours on Sunday.

Detailed Forecast

Forecast for the Cascade West Slopes

A relative short break in the weather should be seen much of Sunday with some light snow showers so conditions shouldn't change too much on Sunday.

This forecast will err on the side of caution and emphasize the avalanche danger in the Mt Baker area on Sunday.

There is still a lot of variation in snow cover depending on elevation since it is early in the year. Expect winter conditions at the higher elevations and too little snow for avalanches at the low elevations.

Note that the next system is due to begin to arrive late in the day on Sunday. Be prepared to ratchet back your plans if conditions get stormy again before the end of the daylight hours on Sunday.

 

Snowpack Discussion

Weather Discussion for the Cascade West Slopes

There  has been a lot of variation depending on location in weather and snow conditions in the Olympics and Cascades the past couple days.

Snow has been heavy in the Mt Baker area where the NWAC station at the ski area has had 62 inches of snow in the past 4 days ending Saturday morning with a warming trend which spells avalanches there.

Snow amounts have been less elsewhere along the west slopes with about 7-29 inches in the past 4 days with the most at Paradise and with little for the 24 hours ending Saturday morning.

Decreasing south winds and a cooling trend should be seen on Saturday as a weakening front shifts to the east. About 5-10 more inches of snow is likely on Saturday in the Mt Baker area and perhaps about 2-5 more inches should be seen elsewhere.

Recent Reports for the Cascade West Slopes

The Mt Baker pro patrol reported local natural and widespread sympathetic and remote ski triggered wind or storm slab avalanches on Saturday morning. These were mainly on north to northwest slopes in the 4500-5000 foot range since this is the avalanche terrain of the ski area.

Some reports for Friday via the NWAC Observations tab for the Crystal Mountain area indicate some recent upside down surface layers with some clean shears in pit tests and some ski triggered wind slab avalanches up to R3/D3 in size.

A skier was caught but not injured in triggered storm slab avalanche on Mazama Ridge near Paradise on a 35 degree southeast facing slope at about 6000 feet on Friday. The slab was about 10 cm x 30 m wide and the debris remained soft and fortunately there was a safe run out without obstacles such as trees or a terrain trap.

Mazama Ridge avalanche from Friday. Photo courtesy of Radka Chapin.

 

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.