Avalanche Forecast

SAT AM update:  Cornices have grown large over the last week and have not had much time to settle since the end of the storm cycle. Give cornices a wide berth as they often break further back than expected along ridgelines. Cornices may also provide a trigger to set off large avalanches not likely to initiate under a skier's weight. 

Northwest flow will help carry a weak low pressure system northwest to southeast across the Olympics and Cascades on Saturday. In the Olympics this should mainly cause west northwest winds with some light snow in the morning, becoming light to occasional moderate in the afternoon, with cool temperatures. New shallow wind slab seems possible on lee slopes mainly at higher elevations. New storm slab would be be found on sheltered slopes but should be shallow and unlikely.

Layers from the past 11 days should continue to stabilize. Possible older deeper wind slab may linger on previous lee slopes mainly at higher elevations. Watch for signs of firmer wind transported snow.

Previous older deeper storm slab on sheltered slopes should be mostly stabilized and unlikely by Saturday.

The sun is starting to get stronger as we head toward March. Watch for sun effects such as roller balls and pinwheels on solar slopes that could trigger a loose wet or a wind or storm slab layer on a steep slope.

It will have been many days since there have been many people in the back country so conditions are a bit uncertain. Careful snow pack evaluation and caution should still be essential on Saturday.

Recent Northwest Weather

An extended mild and dry period occurred the latter half of January generally causing a crust to form in all areas. Very cold weather followed in early February which generally produced low density snowfall and faceting near the crust.

During the past 11 days the Pacific Northwest has been pummeled almost daily by frontal systems producing periods of strong winds and heavy snowfall. The water equivalent over the past 11 days is about 7 inches with snowfall about 5.5 feet at the NWAC weather station at Hurricane.

Observations for Washington Cascades near and west of the crest

Several avalanche cycles have been seen the past 11 days. West of the crest the January crust has become pretty deeply buried and there isn't any recent natural or human triggered activity down to that layer lately. Attention near and west of the crest will be focused on recent storm layers.

A cold front Tuesday evening caused heavy loading rates at gradually warming temperatures. This caused a widespread natural avalanche cycle that was seen in many areas by Wednesday morning with numerous wind and storm slab avalanches noted from the Mt Baker, Snoqualmie Pass and Crystal Mountain ski areas. Some of the avalanches were up to 3-5 feet deep!

The last front of the 11 day storm cycle moved past on Wednesday night causing denser snow at warmer temperatures. Easy ski triggering of storm slabs on Thursday up to about 1-1.5 feet mainly on lee slopes was reported by ski areas including Mt Baker and Alpental.

West northwest winds and light snow showers are decreasing on Friday. No new natural or human triggered avalanches have been reported so far on Friday. But winds on summits and ridges are locally strong enough (for example at the top of Crystal or White Pass) to build local wind slab on lee slopes on Friday.

Road side roller balls and small wet loose on solar slopes at Hurricane on Friday by Katy Reid.

The mid and base pack at Hurricane should still consist of mostly stable crusts and melt form layers from periods of warm weather earlier this winter.

Keep an eye on your riding partner until the deep new snow further settles and the risk of SIS subsides.