Avalanche Forecast

Moderate rain and snow late Wednesday should taper to light to moderate showers with a cooling trend overnight Wednesday and Thursday.  

Increasing crest level winds are expected Wednesday night and Thursday. 

The avalanche danger will lower slightly Thursday, but it will take time for these deep storm slab layers to stabilize, mainly at lower elevations with little wind exposure. Near and above treeline, strong winds should continue to build wind slabs along lee slopes below ridges and exposed open terrain.

Dangerous avalanche conditions will persist due to the likelihood for triggering a large and potentially deadly avalanche. Recent storm and wind slabs will require time to heal, so be patient and match your terrain selection appropriately, namely very conservative.

Significantly transformed snow conditions have taken place during this extended storm cycle. Tree-well and snow immersion hazards are very dangerous, so keep communication with your partner at all times.

An extended storm cycle continues. Over the past 7 days, 3 to 4+ ft of storm snow has fallen over a strong rain crust buried 1/16. Mt Baker has been the exception with over 8 ft of storm snow received in the past week!

Warming early Wednesday, along with heavy snowfall and strong winds led to a natural avalanche cycle. Slab avalanches of 1-2 ft were common.

Dense storm slabs built quickly early Wednesday, forming over weaker storm snow. 

Below the recent 2 ft of storm snow, 3-4 ft or more of gradually settling snow sits above the most recent melt-freeze crust - it is very deep out there! 

Poor visibility and frequent storm conditions have limited observations above treeline during this period. 

Observations

Central

On Wednesday, NWAC professional observer Jeff Ward traveled in wind sheltered terrain below treeline, just east of Stevens Pass, finding 2-2.5 ft of storm snow. In this terrain with little to no wind effect, the storm snow had a favorable density profile of gradually increasing density with depth. No reactivity was found in tests within the gradually settling storm snow. 

On Wednesday, NWAC Pro observer Ian Nicholson traveled in the Kendall Trees near Snoqualmie Pass. Warming early Wednesday formed sensitive storm slabs with several natural storm slabs releasing about 12-16" on a storm density change.

Natural storm slab release on sheltered slope below treeline, Wednesday, 1/24. NWAC observer, Ian Nicholson

On Tuesday, NWAC avalanche forecasters  in the Skyline ridge area (near treeline and below) reported 3' of snow received during this storm cycle sitting above and well bonded to the 1/16 crust. Higher intensity snowfall began creating shallow storm slabs in the afternoon, with cracking observed generally in the new shallow snow, but occasionally breaking down to an older storm instability about 1' deep. East winds were transporting snow.  A professional in the Smithbrook area also reported increasing wind transported snow near treeline and one skier triggered soft slab avalanche on a south aspect near 5000'. 

On Tuesday, an avalanche professional in the Alpental Valley/Source Lake area observed slabs becoming reactive 10" down by early afternoon and still building. Moderate to strong winds were transporting new snow throughout the day. 

South

Professionals in the Crystal area Monday reported 1 to nearly 2 ft of snow above the 1/16 crust in wind sheltered terrain generally well bonded. In areas stripped of snow during Sunday's storm, less than 8" sits above the most recent crust and is poorly bonded. Loose dry avalanches were the biggest avalanche problem encountered Monday, found in steep terrain at higher elevations and easily ski triggered with the potential to run long distances.