Friday into Saturday is a major weather transition period. Expect high precipitation amounts, warming temperatures and a rapidly rising avalanche danger.
A new and growing wind slab will become touchy to triggering as new snow fall driven by increasing southwesterly winds begins to land on a variety of old hard surfaces.
No new avalanches have been observed or reported in since Monday Dec 19th. Continue to support your backcountry community and please consider submitting a MIN report, Your information sharing is vital.
New snow and increasing southwesterly wind will begin to bury old surfaces. These surfaces are generally very hard and in places the snow has been stripped to the ground. Expect areas just below ridgetop on northerly aspects to begin to rapidly accumulate snow as strong south westerly winds are forecast to continue. In some parts of this forecast area, a crust exists on south aspects. As the temperatures have continued to remains very cold, faceted surface snow in protected lower elevation terrain is present.
A layer of large surface hoar crystals, buried in early December, is found down 20 to 50 cm. This layer has previously produced small but remotely-triggered avalanches.
The lower snowpack is well consolidated above the mid-November crust, found at treeline below 1200 m.
A cold arctic air mass over the region will continue to bring to the forecast area, gusty outflow winds through the coastal inlets and extremely cold temperatures. Beginning Friday, a series of weather systems are expected to deliver in excess of 70 cm of new snow with potentials for amounts greater than 100 cm. A rapid rise in temperature and freezing level is expected Saturday with models indicating a brief period of above freezing at 2500 meter elevations.
Thursday night
Snow 5-10 cm. Northeasterly wind, switching to Southeasterly wind that will build to 50 km/h at ridge tops. High of -15˚C.
Friday
Snow 25-40 cm. Southwesterly wind building to 70 km/h at ridge tops. High of -20˚C.
Saturday
Snow 30-70 cm. Southwesterly wind building to 100 km/h at ridge tops. High of -7˚C.
Sunday
Snow 5-10 cm. Southwesterly wind 50 km/h at ridge tops. High of 0˚C.
More details can be found in the Mountain Weather Forecast.
