Avalanche Forecast

A weak frontal system should spread light rain and snow over the area tonight along with gradually lowering snow levels overnight. Light precipitation should taper off Tuesday afternoon.   

Generally light precipitation and a cooling trend should not greatly increase the avalanche danger on Tuesday.  However, precipitation amounts with this pattern have been poorly handled, so watch for shallow wind and storm slabs mainly in the near and above treeline zones. Moderately strong W to NW winds in the alpine overnight may develop new wind slab on lee N thru SE aspects. 

After an extended cold and dry period earlier this month that allowed faceting of the near surface snowpack the weather pattern lately has been characterized by stretches of dry weather and infrequent and mild weather systems - very different than Dec 2012.  This pattern has helped stabilize the snowpack as a whole but has done little to help those areas and elevations without much snow.

The last storm cycle and associated avalanche activity occurred following a series of frontal passages and warming temperatures from December 20-23. This caused 1-2 feet of heavy snow in the alpine and some very wet snow and rain near and below treeline. Sensitive wind slab was reported by pro patrol at Mt. Baker and a professional guide near Chair Peak (Snoqualmie Pass) reported a size 2 natural wet slab release.  

Recent observations over the past few days include stable surface crusts, a few minor wet-loose triggered avalanches on solar aspects near and above treeline as well as some settled powder near treeline on non-solar aspects. Snow profiles and tests at Alpental Thursday showed generally stable snow well bonded snow but a few high quality but hard to trigger shears were noted about 60 cm below the surface above old crust layers within softer melt-form crystals.

NWAC professional observers digging deeper on Sunday 12/29 reported a series of rain and melt-freeze crusts throughout the snowpack that were generally well bonded to the intermediate layers (rounds or polycrystals). See the picture below illustrating the # of crusts identified in a snowpit dug by NWAC observer Jeff Hambleton at Table Mtn (S aspect, 5500 ft) near Mt. Baker.  

Light rain seen mainly from Stevens Pass down to Mt. Rainier on Monday likely caused some small wet loose slides on steeper north facing slopes that still had available loose snow.  

The avalanche danger will continue to be low at the lower elevations due to our ongoing lower than normal snowpack. Non-avalanche hazards such as exposed rocks, creeks, and icy surfaces exist and present a travel challenge.