Avalanche Forecast

The avalanche danger will shift to new Wind and Storm Slabs formed with and after a cold frontal passage overnight Wednesday. Periods of moderate winds with light to moderate snowfall at cooling temperatures will make triggered slab avalanches possible by Thursday, especially on steep slopes receiving wind transported snow. Use visual clues such as fresh cornices, wind drifted pillows and cracks in the snow all indicating that you could trigger a Wind Slab avalanche. 

The cooling temperatures will allow for old wet snow to consolidate and refreeze, limiting any Wet Snow avalanches. 

On northerly aspects near and above treeline, continue to look for and test persistent weak layers within the upper two feet of the snowpack. A refreezing upper snowpack should make lingering persistent weak layers more difficult to trigger but use caution and evaluate the snowpack especially on large open north facing slopes near and above treeline.

New wind and snow is arriving at cooling temperatures late Wednesday. This is allowing old wet snow to begin re-freezing while building new shallow wind and storm slab layers.

Very warm temperatures and sunshine Monday quickly allowed the weekends 6-12 inches of snowfall to become wet and weak, causing widespread wet snow avalanches on many steep slopes on all aspects. The majority of these avalanches were Loose Wet but several large Wet Slab avalanches released on some steep slopes as well.

Older layers of weak snow may still be found in the snowpack. We have one recent observation from the East Slopes - Central zone that identified buried surface hoar 2 feet below the surface at 6800 feet and still reactive in snowpack tests. If you have any information or observations on layers within the snowpack please consider submitting them to NWAC via our public observations page. The exact weak layer and depth depends on your location. Common weak layers found over the last month: 

• 3/25 and 3/22: Buried surface hoar layers found on shaded aspects near and above treeline.
• 2/13 Facets above a firm and thick melt-freeze crust can be found in many locations near and above treeline. This layer is thought to be dormant at this time but may re-awaken with a substantial weather input.

Lower elevations further east of the crest have melted back for the season and no longer present an avalanche risk. 

Observations

North

No recent observations. 

Central

On Wednesday, NWAC professional observer Matt Primomo traveled in Hawkins Mountain area. Below 5500 ft about 1 ft of wet surface snow was making Loose Wet avalanches possible on steep slopes. Above about 6000 ft firmer surface snow was limiting the Loose Wet avalanche potential. No Wind Slabs were scene near ridgelines, lacking available snow for transport. There were widespread large wet snow avalanches following the weekends storms, likely releasing Monday during warm and sunny weather. The upper two feet of snowpack has undergone a spring transition to melt-freeze grains.

On Monday, a public observation from the Entiat River drainage reported wet snow in the upper 16 inches (40 cm)  of the snowpack on a NE aspect at 6800 ft. Below this, colder drier snow was found with buried surface hoar 2 feet down (60 cm). This layer was reactive in snowpack tests, suggesting propagation was possible. The 2/8 crust was 3 feet (1 m) below the snow surface and breaking down. S through E aspects had a more springlike and consolidated snowpack. 

On Friday 4/6, professional observer Matt Primomo traveled up the Icicle to above Colchuck Lake. Matt found a moist and well settled snowpack below 5800' with no persistent weak layers. The 2/8 crust was 1 m down.  At 6700' on a NNE aspect, Matt found preserved stellars 14 in (35 cm) down and showing a likelihood to propagate in snowpack tests. Dry snow was found at this elevation below the top 8 " (20 cm). Higher in the terrain, recent wind slab avalanches likely released on this layer. Matt also observed natural loose wet avalanches and one wet slab avalanche above treeline on a SE aspect.