Avalanche Forecast

A cool upper trough should pass the Olympics early Monday with cool but drying northwesterly flow expected through the day Monday.  A few light snow showers early Monday should give way to partly to mostly cloudy conditions with continued strong northwest winds lasting through the day.

This weather should allow for the older wet snow to form a more solid underlying crust which may act as a sliding surface.  The strong winds should transport recent snow, mainly above treeline but look for transported snow near tree line as well.  Winds should shift to more northwesterly Monday so watch for wind slab formation on east to south facing slopes.  

Storm slabs should begin to slowly stabilize Monday but should remain a concern and expect triggered slides to remain likely on steeper open terrain where cautious route-finding and conservative decision making will be essential.  

A stalled moist  frontal boundary has been draped over the Olympics since Saturday afternoon.  This caused very strong winds late Saturday with moderate precipitation and a snow line near 5500 feet causing rain and wet snow conditions late Saturday near and below treeline as reported in the Hurricane Ridge area by observer Katy Reid.  Temperatures cooled overnight and through early Sunday depositing about 1 foot of new snow at Hurricane Ridge by Sunday morning with diminishing winds.  

Given the weather since Saturday, I expect to see new wind slab formed on lee terrain near and especially above treeline where most of the precipitation fell as snow during the very windy period. The bonds of new snow to a refreezing crust should be good given the slow cooling trend. 

Storm slabs should be found on all aspects and elevations, especially with daytime warming and continued snowfall Sunday afternoon.   

A NPS ranger reported 9 inches of moist new snow as of Sunday morning over a slowly refreezing crust at Hurricane Ridge.  A few more inches of snow likely accumulated during the day down to around 4000 feet with some possible wind transported snow likely above treeline where westerly winds are expected to be stronger.

While composing the forecast I just received word from a Park Ranger at Hurricane Ridge reporting a backcountry skier on Sunrise Ridge above the road Sunday afternoon was able to ski cut and release a storm slab about 15-20 ft wide that covered the uphill lane with debris. Fortunately the skier was not caught in the slide. This confirms that the daytime warming Sunday anticipated did indeed lead to warming of the surface snow layers creating unstable storm slab conditions.