Avalanche Forecast

Light to locally moderate snowfall developing on Wednesday along with and moderate winds will create heightened avalanche danger on wind loaded slopes near and above treeline. 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. 

Below treeline you may still trigger Loose Wet avalanches or they may be triggered by additional rainfall. Watch for signs of wet snow conditions such as sluffing, roller-balling and any natural Loose Wet avalanches as signs of an increasing hazard. Avoid terrain traps if you suspect you could trigger a Loose Wet avalanche. Loose Wet avalanches may still become large in isolated areas if they gouge down to deeper layers of moist or wet snow.

Be cognizant and avoid exposure below unsupported slopes as the potential for Glide Avalanches will increase during prolonged rainfall and above freezing temperatures at lower elevations. Use extra caution and avoid stopping near and below snow covered rock slabs where Glide avalanches could occur. 

A front brought light to moderate rain and wind to the west slopes of the Cascades Tuesday. Rainfall was locally heavy in the Mt. Baker area during the day. Snow levels fell to around 5000 ft by late Tuesday afternoon. Monday was warm with filtered sunshine. The dry weather followed the strong weekend storm which initially pushed rain into the near and above treeline elevations bands early Saturday. Cooling and significant new storm snow followed through Sunday afternoon with 1 to 2+ ft of snow above 4000-4500 feet. There was a significant snowfall gradient with elevation with this spring storm. Wet snow avalanches were seen earlier in the storm and continued at lower elevations through the weekend. New Wind and Storm Slabs developed at higher elevations later in the weekend with fresh cornices developing along ridgelines.   

Moist or wet snow in the upper snowpack should begin to refreeze near and above treeline Wednesday as colder air arrives. The 4/1 firm crust may still exist in some areas, it has most recently been identified in the Crystal area 1.5-2 ft down. 

Out of the weak layers that we've tracked through the season, the 2/8 crust can still be identified in many areas 5-7 feet below the surface. This interface was associated with the 2/13 facets. Though it's unlikely, if significant water pools on the crust, it could result in very large and dangerous Wet Slabs.

Observations

North

No recent observations

Central

Stevens Pass DOT and Stevens Pass Pro-patrol reported large and destructive avalanches during control work that released as soft slabs with explosives and quickly entrained wet snow at lower elevations on Monday. In a section of the ski area with minimal skier traffic on the east end of Cowboy Ridge, this explosive triggered slide (SS-AB-D2.5-R3-O) on a north aspect produced 4-5 ft of debris as it entrained old saturated snow below.  

Pro-observer Matt Primomo observed recent natural wet snow and storm snow avalanches in the Stevens Pass backcountry over the weekend, including this recent Litchenberg Wet Slab Avalanche on a SE aspect at 5200'. 

Pro patrol at Alpental Sunday reported about 1 ft of new storm snow that was sensitive to ski triggering, releasing soft slab avalanches of 8-12" and running long distances, entraining all the recent snow, running on the old wet snow surface. At lower elevations the new snow was easily releasing as Wet Loose avalanches by skis. 

South

NWAC professional observer Jeremy Allyn traveled in the Crystal backcountry Monday 4/9. Through mid-day, Jeremy found poor travel conditions as the surface crust quickly broke down with moist or wet snow in the upper snowpack.  Recent large Wet Loose and one Wind Slab avalanche from the weekend were observed in surrounding terrain.