Avalanche Forecast

Showers and winds should briefly ease overnight before a warm front beings to spread additional rain and snow over the area on Sunday. The timing of the heaviest precipitation is uncertain on Sunday, but snow levels should stay cool - below pass level - through late morning, before rising quickly in the afternoon.

The avalanche danger will remain elevated through Sunday, with danger increasing strongly in the afternoon as denser storm and wind slab develop. Choose conservatively on Sunday; new storm snow from Saturday will not have had much time to settle,  be aware for wind loaded slopes well off of ridges onto lee N thru SE slopes, be ready for warming temperatures to create a unfavorable a new snow profile later Sunday along for the potential for wet snow avalanches late in the day at lower elevations.  Also, give new cornices a wide berth as they have had neither time to settle and will also be subject to warming late in the day.  

    

The first significant storm cycle of 2014, and more recently in the last 3 weeks is coming to a close this weekend. The first system to flatten the dominant upper level ridge during this pattern moved into the Pacific Northwest Tuesday with moderate snow levels and mixed precipitation, including freezing rain for Stevens and Snoqualmie Passes.  

For the west slopes of the Cascades, a generally favorable mid and lower snowpack exists, even if it well below seasonal norms, consisting of various crust layers, rounded grains, and melt-freeze crystals. The exception to this was a reactive rain crust, that was involved in a few avalanches last Saturday on an east-facing slope on Chair Peak near Alpental and on Mt. Herman near Mt. Baker. 

A stronger system moved across the region on Wednesday, depositing 6-18 inches of snow, with an overall cooling trend Wednesday that helped new snow bond to older crusted surfaces and built mostly favorable new snow profiles. Thursday continued the trend with cool snow levels and showers persisting during a relative break in the action. Mt. Baker seemed to an local area of instability - a size 2 soft slab avalanche, skier triggered, on a south facing slope of Table Mountain was reported on 1-10-14 and was believed to release on a sun crust formed from last the weekend.  Also, a NWAC observer in the Swift Creek drainage near Mt. Baker reported a storm slab releasing on a layer of graupel within the recent snow.  

An occluded front crossed the Northwest late on Thursday. NWAC sites near and west of the crest had snowfall mostly in the 3-9 inch range. This snow was generally wet and heavy with remarkably high water equivalents. 

Avalanche control results from the ski areas were variable on Friday morning with the most active results from Stevens and Alpental with localized 6-12" soft slab releases and one 2' heavy slab release on lee slopes mainly via explosives.

During a wet, warm and windy Friday night, rain crept up to about 4500' in the north, 5000-5500' in the central Cascades and 6000' in the south, a cold front came through Saturday morning, dropping snow levels down to around 3000-3500' Saturday.  Heavy showers and strong west winds, along with another 0.5-1.0 inch of water through the daylight hours likely built new unstable wind slab in the near and above treeline zones. Expect wind-scoured windward slopes above tree-line. The strong convective nature of the showers today and this evening with varying precipitation rates likely introduced instabilities within the new storm snow as well.  

NWAC observer Dallas Gallas in the Stevens Pass area @ 3600 ft on a S aspect reported sudden collapse fracture about 2 ft (60 cm) down on the most recent rain crust performing a CT and an ECT. Alpental pro patrol reported strong wind transport to lee slopes well down to mid mountain, an upside down snowpack in the recent storm snow and a moist upper snowpack below about 4500 ft. Additional snow accumulation is expected Saturday night with a gradual cooling trend.