Avalanche Forecast

Cooling overnight Friday with light rain showers changing to light snow showers. Showers should end by midday Saturday with further cooling and light winds.

The moist to wet snow surface will begin forming a new crust with only light amounts of fresh snow expected above. This should not lead to an overall increase in danger, especially at near and below treeline elevations.

In the passes, shallow new snow should bond well to the extensive freezing rain crust. 

Light snowfall and higher winds may occur at the upper elevations in the above treeline band. As snow begins to accumulate Friday night and early Saturday, keep watch for developing wind slabs on northerly to easterly facing slopes, mainly if greater new snow is received than forecast.

Early season hazards still exist. Many creek beds have still not filled in for the winter.

Be cautious when travelling on slopes with an exposed slick surface crust due to fall hazard, mainly in the Cascade passes. 

Light to moderate rain fell to crest level Friday. Rain has fallen on a very strong and well settled snowpack and likely did little to change the overall avalanche danger, which remains low in most areas.

Over Stevens and Snoqualmie Passes, extensive freezing rain began overnight Thursday and continued through the day Friday. This major freezing rain event has coated the landscape, including the snow surface, with a thick coat of ice, prompting both Stevens and Snoqualmie ski areas to close early Friday due to unsafe travel conditions. Expect this crust to create poor travel conditions in the passes as well as creating an uncontrolled fall hazard where exposed. 

Despite the variable surface conditions, reports indicate a strong upper snowpack with no notable layers of concern. Mild weather over the past several days has allowed for lingering weakness to gain strength, causing a diminishing avalanche hazard.

Observations

North

NWAC Pro observers were on Shuksan Arm on Wednesday. A melt freeze crust was present on all aspects with variable thickness. The 12/29 rain crust was observable on all aspects down approximately 8".

Central

On Wednesday, an avalanche professional was on Rock Mountain in the Stevens Pass area observed reactive wind slabs on a NE aspect at 5300' just below a ridge. A small loose-wet avalanche cycle did occur during the day on solar aspects above 5,000'. Snow was being eroded from E winds in the above treeline zone. Below 4000', faceted snow was seen both above and below various crust layers in the upper snowpack.

On Wednesday, a NWAC forecaster was in the Alpental backcountry and noted an overall strengthening snowpack. The top 4" of snow is poorly bonded to the very supportable 12/29 0.5" freezing rain crust. Travel was very difficult with loose snow over a very firm, slick bed surface! Small loose wet slides were on SE-S-SW aspects on steep, rocky, sunny slopes

South

On Wednesday, Professional Observer Ian Nicholson was in the Crystal backcountry and found breakable crusts and sun-affected snow.  Steeper solar slopes were capable of producing huge roller-balls but dry snow remaining on NW through NE aspects. He did get a rather stiff wind slab to break cleanly down 20 cm on a specific terrain feature near treeline.