Avalanche Forecast
Regions: Cascades - South West.
Look for signs of recently wind transported snow such as uneven snow surfaces, fresh cornices, and snow drifts. Identify and avoid areas where wind loaded slopes exist. Recent strong winds may have loaded slopes well below ridgeline.
Detailed Forecast
Expect Sundayâs clearing and mild weather to allow the snowpack time to gain strength.
Newly formed wind slabs will continue to be a problem into Sunday. Look for areas of recently wind transported snow such as fresh cornices, snow drifts, and uneven snow surfaces. Identify and avoid locations where recent wind loading has occurred. Strong ridge top winds may have loaded slopes well below ridgeline. While we expect wind slabs to primarily exist near and above treeline, keep a watchful eye out for exposed terrain features below treeline where wind slabs may have formed.
Wind slabs can be deceptively difficult to manage in the terrain. Take a moment and read our recent blog post by NWAC Pro Observer Jeremy Allyn on wind slabs.
Warming temps and sunny skies may allow for small loose wet avalanche to occur on steep sun exposed terrain late in the day. Be mindful of steep sunny slopes, especially near rocks where these loose avalanches are most likely to occur.
Despite all this new snow, early season hazards still exist. Many creek beds have still not filled in for the winter.
Snowpack Discussion
Saturday afternoon brought  to a close a very active storm pattern which began Thursday.
Several inches of new snow from Saturday now sits above a rain crust formed during Fridayâs warmer weather. Strong winds Friday night and Saturday morning redistributed much of the recent snow, leaving behind a variable snow surface. Soft storm snow, breakable crust, and stiff wind slabs can all be found in the backcountry.
Below the 12/30 rain crust a generally strengthening snowpack can be found. Weather stations from across the region confirm the upper snowpack is settling and observations demonstrate that it is gaining strength.
Observations
North
On Saturday Mt Baker Pro Patrol reported wind transportation of the new snow at the upper elevations forming small shallow slabs. Evidence of rain was found to the top of the ski area and a natural loose wet avalanche cycle occurred in the surrounding backcountry overnight Friday, likely during the rain event.
NWAC pro observer Lee Lazzara on Bear Paw Mountain Saturday. Lee reported a variety of snow surfaces conditions due to recent wind transportation of snow. He observed wind slabs up to 2 ft thick sitting on a firm rain crust formed during the overnight rain event. Snowpack test produced highly variable results in the upper snowpack, however no observations indicated significant layers of concern.Â
South
On Saturday NWAC Pro Observer Jeremy Allyn was in the Crystal backcountry. He observed evidence of rain in the form of a breakable rain crust all the way to ridge crest. Recent winds had redistributed the overnight snow forming pockets of wind slabs on lee slopes. Jeremy noted that variable snow surface conditions exist due to the recent wind event.
Avalanche Problems
Wind Slabs
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.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1