Avalanche Forecast

Competing factors on Wednesday will keep dangerous avalanche conditions in play despite a relative break in the storm cycle and a favorable temperature trend.  A cooling trend overnight Tuesday and continuing on Wednesday should build lower density snow on top of Tuesday's storm slab and allow new storm instabilities to slowly settle. Moderate westerly winds will continue to load lee easterly aspects throughout the day Wednesday. South to southeast winds ahead of Tuesday's frontal system near the passes may have cross loaded slopes before winds switched to westerly so NW aspects have been added to the wind slab concern.  

Expect snow conditions to still be touchy on Wednesday and human triggered avalanches will be likely mainly on lee NW thru SE aspects. Triggered avalanches are likely to start and stay in the new snow from yesterday...but the potential exists for very large avalanches in specific areas that release down to older storm and stiffer wind slab layers or the rain crust from last week. Recently formed and sensitive cornices along ridgelines are an example of a natural trigger that could be large enough to trigger a much deeper and very destructive slide.

Stick with conservative terrain choices for another day and let all the recent snow and associated water weight received over the last week a chance to settle.  

Recent Northwest Weather

An extended mild and mostly dry period occurred over the latter half of January which allowed a variety of crusts to form. Very cold weather followed in early February which produced low density snowfall and strong temperature gradients in the upper snowpack that allowed near surface faceting and broke down previously strong crusts buried in late January. During the last week the Pacific Northwest has been pummeled almost daily by frontal systems producing periods of strong winds and intense snowfall accumulation at fluctuating and generally moderate snow levels.

Water equivalents in the Olympics at the NWAC weather station and the NRCS Snotel at Waterhole over the last week are 6-7 inches with snowfall around 5 ft. Expect wind loaded slopes to hold much more new snow from the past week than the generally sheltered weather stations.  About 12" of new snow has fallen in last 12 hours ending 5 pm Tuesday.  

Observations near Hurricane Ridge

At Hurricane Ridge this weather has been building deep new snow over a rain crust from Wednesday, which lies over colder lower density snow from earlier in February. In sheltered non-solar aspects, surface hoar may be buried above the late January crust.

A park ranger and NWAC observer Tyler Reid at Hurricane Ridge Friday reported one ski triggered D2 avalanche on a northeast slope at 5200 feet on Friday.

Snow pit tests by Tyler on Saturday on a SE aspect @ 5200 ft gave moderate to hard, sudden planar results with potential to propagate across the failure plane on the melt freeze crust 20 cm down (this layer is now further down).  You can view a great video by Tyler explaining his test results. 

A natural avalanche, estimated at size D2-3 with up to a 3' crown was visible below the Hurricane Ridge road at about 5100 ft on a wind loaded NE aspect on Monday.

Limited snow at the lowest elevations will limit the avalanche danger but be aware that avalanche paths on solar aspects and lower elevations are finally beginning to fill in. The mid and base pack should still consist of mostly stable crusts and melt form layers from periods of warm weather earlier this winter.