Avalanche Forecast

A weakening front and a weak surface low will move across the Northwest Sunday night. The main snow should be seen in the south Cascades and mainly at Mt Hood. Light amounts of new snow if any are expected along the Cascade west slopes. Paradise might get a few inches. Watch for a change Monday to light to moderate W-NW alpine winds, with a change to light west winds in the lower Cascade passes by Monday. Temperature fluctuations could be a little problematic.

So not a lot of change is expected on Monday. This should mainly continue to allow recent storm snow to gradually stabilize.

Keep an eye out for previous or newly forming wind slabs on Monday. Winds will have potentially load non-traditional aspects. If you see signs of winds transporting snow including plumes, drifts, and uneven snow surfaces, then avoid slopes where the wind loading is occurring.

From the Tatoosh observations above it looks like loose dry avalanches are possible. We won't list it until the problem seems more widespread. Watch for unconsolidated loose snow deeper than a few inches on steep slopes. These avalanches are most dangerous above terrain traps.

There is a lot of deep soft snow out there from the past week. Unconsolidated snow, particularly around small trees, can present a non-avalanche snow immersion hazard. Keep visual and verbal communication with your travel partners when traveling in treed terrain.

Also despite all this new snow, early season hazards still exist at lower elevations and especially around creek beds that are not filled in.

Moderate to strong E-SE  crest level winds have been seen late Saturday and Sunday with light to moderate E winds in the lower Cascade Passes.

About 1-11 inches of light snow fell across the west slopes of the Washington Cascades and Passes in the 24 hours ending Saturday morning with the most in the southwest Cascades. This added to the very impressive 1-4 feet that fell across the same area early in the week. Recent deep storm snow has been settling and stabilizing over the last several days. Numerous field observations from throughout the west slopes of the Washington Cascades indicate that storm layers continue gradually stabilize.

Moderate to strong SW-W crest level winds transported snow in exposed terrain Tuesday to Thursday forming wind slabs on a variety of aspects.

In general, 2.5 to 3.5 feet of increasingly firm snow now sits above the 12/15 layer. Observations have not demonstrated consistent layers of concern within the upper snowpack. 

Observations

North

On Saturday a skier via the NWAC Observations page for Mt Herman did not note any signs of instability.

Last Wednesday, the Mt Baker Pro Patrol observed significant wind transport on exposed terrain features mainly above treeline as ridge top winds increased. There was a 2 foot human triggered slab avalanche that propagated about 45-75 feet wide near ridgeline.

Central 

The Alpental pro patrol on Sunday reported shallow wind slab forming due to east winds.

Another skier on Humpback Mountain via the NWAC Observations page for Saturday reported getting caught by a small 2 foot wind slab on a W facing slope near the summit. No serious injuries were reported. Note that areas west of Snoqualmie typically have stronger winds during periods of offshore flow.

NWAC pro observer Jeremy Allyn was in the Chair Peak - Mt Roosevelt area on Saturday and reported windy conditions on the shoulder of Chair Peak. His party triggered 2 small wind slabs on the north slope of Chair Peak at about 4800 feet. Storm layers are healing slowly due to cold temperatures.

The Stevens pro patrol on Saturday found moderate CT result in storm layers, with hard or no results on the 12/15 layer down 85-90 cm in north slope pits at 4800 and 5800 feet. No wind slab was observed.

NWAC forecaster Robert Hahn was on Jove Peak on Friday and found deep trail breaking, small subtle wind slab on the ridge, storm slab no longer an issue, no signs of instability and good skiing.

A public observation from Stevens Pass Thursday reported triggering very small isolated wind slabs in wind loaded terrain. The party also noted a mostly right-side-up snowpack that was gaining strength.

South

Yet another good report via the NWAC Observations page from the Tatoosh on Saturday reports several triggered D1-1.5 loose dry avalanches on various steep slopes.

Professional observations from the Crystal Mountain backcountry Wednesday and Thursday are consistently demonstrating a well bonded and strengthening snowpack. Many newly formed cornices along the ridges failed easily under a travelers weight.