Avalanche Forecast

Snow showers should end overnight Sunday, giving way to clearing skies and continued cold temperatures. Strong NE-E ridgetop winds should continue to transport the ample loose surface snow and build touchy wind slabs on more non-traditional or unusual SE-SW aspects, mainly above tree line and possibly near tree line.

Deep, low density snow will make sluffs or loose slides likely on steep wind sheltered slopes. Watch for travel on steep slopes above terrain traps, such as cliffs or creeks where the entertainment of loose snow may bury someone caught more deeply. 

Fresh, touchy wind slabs near ridges and non traditional aspects, will be the primary avalanche problem on Monday. Wind affected snow should be widespread Monday, especially with strong shifting winds, watch for wind transported snow on a variety of aspects and cross loaded features.

The 12/17 PWL persistent slab problem is becoming more deeply buried and less sensitive in snowpack tests and has been removed from the avalanche problem set.

Weather and Snowpack

Strong storms around the Solstice deposited generally 1 to 2 inches of water equivalent along the west slopes. A period of rain or freezing rain (Snoqualmie) during this storm cycle allowed crust layers to form in the Baker area from 4000-4500 feet, the Passes up to around 5000 feet (Stevens) to 6000 feet (Snoqualmie) and 6000-7000 feet in the Paradise area. The crust(s) were especially stout in the Snoqualmie and Paradise areas and very thin in the Crystal backcountry. These crust layers are now much less of a concern and in the Alpental valley on New Years Day, found buried on average, 90 cm (~3 feet).

A strong front and strong west flow aloft was seen over the Olympics and Cascades on Monday and Tuesday. The White Pass avalanche fatality involving a skier triggered storm slab failing on the Solstice crust occurred on Tuesday afternoon. NWAC stations along the west slopes and crest had strong west winds Monday and Tuesday with 1-3 feet of new snow for the 48 hours ending Wednesday morning with a cooling trend.

A warm front Thursday deposited up to 12 inches of snow around Mt. Baker, Stevens Pass and above 5000 feet in the Snoqualmie Pass area. Less snow fell at lower elevations at Snoqualmie Pass due to rain at the onset of precipitation, which formed a thin breakable crust, found about 40 cm (16 inches) in the Snoqualmie area on New Year's Day.  A thin rain crust was also found up to 6000 feet above Paradise Friday morning with 4" snow on top.

Clearing Friday night allowed surface hoar to form in some areas, reported Saturday morning, 12/31 above Paradise on Mt Rainier. Sunshine Saturday may have destroyed this before before buried.

A cold storm began New Year's Eve and through New Year's Day has deposited some 10-15 inches of very cold, low density powder, falling with light winds and a cooling trend in most areas. 

Recent Observations

Consistent observations were received on New Year's Day from three NWAC observer's out enjoying the after champagne, champagne powder! Reports are in from the Mt Baker area, Stevens Pass and the Alpental Valley, Snoqualmie Pass, all reporting amazing deep, low density surface conditions, providing excellent downhill skiing, if after tough up hill trail-breaking.

No triggered slab releases were noted with mostly no slab formations encountered with a right side up snow profile. A good bond to the old snow surfaces was noted with any crust layers buried fairly deeply and unreactive in tests (Solstice crust at Snoqualmie buried 90 cm on average).

All observers noted extensive sluffing on steep descents, mostly the upper several inches of snow. Not necessarily a major concern, however, these conditions should persist in wind sheltered terrain with the continued cold temperatures. 

Alpental patrol performed cornice missions Saturday and easily dropped soft cornices that released only shallow slides within the storm snow on the slopes below, not involving the deeper crust involved in earlier cornice failure Friday.