Stevens Pass

Lingering storm and wind slab should be less sensitive on Tuesday but evaluate recent snow carefully before committing to steeper terrain. Wind slab will mostly likely be found on NW-E-SE aspects near and above treeline. 

Another low pressure system will track across Oregon Tuesday but this one is forecast to bring less snow to the Washington Cascades. Periods of light snow should mainly affect the south Washington Cascades with light showers possible further north. A slight warming trend may occur mid-day. 

Lingering storm and wind slab should be less sensitive Tuesday but evaluate recent snow carefully before committing to steeper terrain. Wind slab will mostly likely be found on NW-E-SE aspects near and above treeline. 

Loose wet avalanches will not be indicated as an avalanche problem but watch for loose wet surface snow if you find yourself on solar slopes during sunbreaks.

Weather and Snowpack

Hopefully the last atmospheric river of the season arrived on Valentine's Day 2/14, causing heavy rain, avalanches, crusts and significant snowpack consolidation through Thursday 2/16 along the Cascade west slopes. Freezing rain also occurred along the lower slopes of the Cascade Passes. A little snow was seen at the tail end of the storm. A short period of fair weather on Friday 2/17 formed another surface crust in many areas. Light amounts of new snow accumulated over the weekend except at Mt. Baker who received a foot of new snow by early Monday morning along with moderate SW winds Sunday night.

A low pressure system tracking across the south Washington Cascades during the day on Monday brought up to a foot of snow in the Paradise/Crystal/White Pass areas with lesser amounts further north. Winds that were easterly in the morning switched to westerly Monday afternoon and were the strongest in the south Washington Cascades. A slight warming trend was observed during the storm Monday.   

Recent Observations

North

The Baker area had an eventful day with pro-patrol reporting a natural avalanche cycle on Shuskan Arm Sunday night. Widespread and sensitive storm slabs 6-10" deep released during control work Monday morning.  A 6" storm slab was skier triggered on a steep north aspect of Table mountain, carrying the skier 100 or more feet. The skier was partially buried and suffered a knee injury. NWAC observer Lee Lazzara was in the Mt. Herman-Artist Point area Monday and found 15 cm (6") of denser new snow poorly bonded to less dense snow from earlier in storm cycle. In wind loaded areas, the slab was up to 60 cm (2') deep.  

Central

The Alpental pro-patrol did avalanche control on Sunday to ensure the slopes were safe for the randonee race and had little results. However, sun breaks and a brief warm up caused a few skier triggered size 1-2 loose wet avalanches in the below treeline band that were sliding on the crust from Friday 2/17.

South

Conditions were quite touchy in the Crystal backcountry Monday. Several reports from East Peak indicated shallow natural and skier triggered loose and storm slab avalanches in the near treeline and upper portion of the below treeline band. One report indicated a slab near the ridgeline of East Peak on a West aspect had released down to the Valentine's Day crust. 

NWAC pro-observer Ian Nicholson was at Paradise on Monday and observed only minor wind transport of new snow. Ian also reported storm slab instabilities were a bit less touchy than in the Crystal area. 

Small natural slab avalanche, East Peak, Crystal Mountain backcountry. Shane Robinson, 2-20-17