Avalanche Forecast
Regions: Stevens Pass.
Sunday may continue to be a tricky day to manage avalanche concerns. Winter like wind and storm slab should prevail at higher elevations with wet loose concerns at lower elevations. Heavier showers and strong spring solar effects can quickly change the snow conditions so pay close attention to weather through the day.
Detailed Forecast
Light occasional moderate showers should be seen on Sunday near and west of the crest with fairly cool temperatures.
Watch for areas of wind slab from the previous couple days lingering on lee slopes. This is most likely on north to east slopes near and above treeline. Watch for signs of cracking or firmer wind transported snow and approach open lee slopes with caution.
New or new storm slab may not have stabilized yet on Sunday. This will be likely on sheltered slopes where there was heavy snowfall or graupel which may have formed temporary weaker storm layers also mainly near and above treeline.
Despite the mostly cloudy weather and cool temperatures on Sunday wet loose avalanche conditions are possible mainly on solar slopes near and below treeline. Watch for wet surface snow deeper than a few inches, roller balls in surface snow and small natural wet loose releases that usually precede more major wet loose snow avalanches. And remember brief sun breaks can quickly extend the wet loose concern to above treeline or to other aspects.  Avoid terrain traps where a small but powerful wet loose avalanche could have unintended consequences.
Snowpack Discussion
Fair weather was seen last weekend through Monday with Monday the warmest day. Reports during this period indicated some powder surviving on north slopes and wet loose avalanches on solar slopes. A crust should have formed on most solar slopes. More sobering was the fatal avalanche Saturday on Granite Mountain near Snoqualmie Pass.
The weather pattern got activated again over the Northwest starting Tuesday. There has been about 1-2 feet of snowfall in the 4 days ending today at higher elevation NWAC stations near and west of the crest. There has been less snowfall and some rain at lower elevations. So it is getting to be a mix of winter like conditions at higher elevations and spring like conditions on solar slopes and at lower elevations.
It took a couple days for the snowpack to get activated again. Here are a few reports for the past couple days.
NWAC observer Jeff Hambelton was near Church Mt on Wednesday. He saw several small but natural and human triggered storm slab avalanches were seen on lee aspects near treeline likely failing within the new storm snow. He was at Table Mt on Thursday and saw widespread natural wet loose avalanches on all aspects with solar effects and daytime warming.
Storm slab on Church Mtn 26 March by NWAC observer Jeff Hambelton.
A front crossed the Northwest on Friday. The Mt Baker ski patrol reported large ski triggered wet loose avalanches on Friday. The Alpental also reported a natural cycle of loose snow avalanches on Friday afternoon which were drier in the upper area and wetter in the lower area. The Snoqualmie DOT reported small to large wet loose avalanches at the highway elevations Friday afternoon and evening. NWAC observer Tom Curtis was at White Pass on Friday and reported 4-8 inch wind slab conditions at about 5800 feet.
Wind slab conditions near White Pass on 28 March by NWAC observer Tom Curtis.
Avalanche activity today has been surprisingly limited give all the recent snow and that it is almost April but we may hear more by tomorrow. Ski cuts today at the Mt Baker ski area gave mainly isolated wet loose avalanches below 4000 feet. NWAC observer Jeff Hambelton on the west side of Mt Baker reported potential wind slab conditions mainly above treeline with active winds and ECT11 SC results at 30 cm in a snowpit on a northwest slope at 5800 feet. Ski cuts on the upper mountain at Alpental gave local small storm slab releases while increasing heavy surface snow over wet snow was reported on the lower mountain.
Avalanche Problems
Wind Slabs
Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 1
Storm Slabs
Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.
Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1
Loose Wet
Release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.
Several loose wet avalanches, and lots of pinwheels and roller balls.
Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 1