Avalanche Forecast

We just can't shake the Considerable rating near and above treeline in this storm pattern despite a favorable cooling trend Saturday and only light to moderate new loading expected. Lingering wind slab formed earlier in the week shouldn't be much of an issue, but once again persistent SE to SW transport winds will build new wind slab on lee slopes Friday night and Saturday. Watch for firmer wind transported snow and be aware of local loading patterns in your terrain. Shallow storm slabs may build late Friday night through Saturday morning.   

Cornices should be less sensitive on Saturday, but they are large so continue to give them a wide berth when travelling along ridgelines since they can break further back then expected. 

The loose wet potential should be minimized by the cooling trend and cloudy skies. If the sun does break out Saturday, mid-March sunshine will rapidly increase the likelihood of loose wet avalanches on steeper solar aspects.  

Powerful glide avalanches remain possible in isolated terrain features such as on steep slopes with smooth bed surfaces and especially where the slabs are unsupported from below.

A cool yet powerful storm system on Sunday may cause high avalanche danger for the southern Cascades by late Sunday afternoon. However, the storm track is uncertain and the avalanche danger will be reassessed with Saturday's forecast issuance. 

Weather and Snowpack

The nonstop active weather pattern continues to push a storm system through the PNW almost every day or two with fluctuating but generally moderate snow levels. The last significant storm impacted the area Wednesday through Thursday with a warming trend that peaked Wednesday night with the frontal passage in the early morning hours and also featured very strong winds seen throughout the Cascade range. Winds decreased Thursday afternoon along with decreasing shower activity. Generally 1.5 to 3 inches of water accumulated along the west slopes in the 36 hours ending 4 pm Thursday. Outside the Cascade Passes, rain reached up to 5000' feet in the north and 6500 feet in the south with snow levels only rising to about 4000 feet at Stevens and 4500 feet at Snoqualmie Pass Wednesday night.  About 4-14 inches of snow accumulated at NWAC stations through Thursday morning. Additional accumulations were light, except above 5000 feet in the Mt. Baker area Thursday where another foot of snow likely fell . 

There remains a significant amount of water in the snowpack. The mid and lower snow pack along the west slopes should generally be a stable mix of crusts and layers of moist and rounded snow crystals.

Recent Observations

Stevens Pass and Alpental Pro Patrol reported an extensive natural cycle Wednesday night. Control results were sensitive and widespread Thursday AM involving new storm snow. As the sun poked out and temperatures rose Thursday, large loose wet avalanches, both natural and skier triggered were reported by the pro patrol in the Stevens area with smaller loose wet noted in the Alpental area. Crystal patrol generally had 1-2 ft slab releases during control work Thursday with large and sensitive cornices along ridgelines. 

In areas that experienced rain Wednesday night, mainly outside the Passes and in the below and near treeline bands, a breakable crust made for tough skiing Thursday.