The snowpack is in a period of transition. Make constant observations of the surface under and around you. Travel with caution where there is a surface crust. Where the snow is wet, avoid snow that pinwheels or snowballs down the slope, or looks and feels like a slurpee.
50-100 cm of snow may have accumulated at upper elevations during the recent storm. Expect deeper deposits in lee terrain due to extreme southerly winds.
A high freezing level brought heavy rain, which soaked and weakened the surface snow. As freezing levels drop, this wet snow will likely freeze into a crust and become less likely to avalanche. Watch for signs of instability like snowballing, pinwheeling, and deep slush on the surface.
On Friday and Saturday, numerous, small, skier triggered wet loose avalanches were reported in steep terrain around treeline.
Most rideable terrain has been soaked by rain during the recent storm. Watch for a new crust to form on the surface as the temperature drops the next few days. Where dry snow remains, at very high elevations, there may be deep, reactive windslabs leftover from the strong to extreme south winds during the storm. In transitional elevations between dry and wet/freezing snow, moderate southeast winds overnight and Sunday morning may form thin reactive windslabs over the new crust.
A crust that was 90-130cm below the surface of the snowpack had been highlighted as a critical avalanche layer in recent snowpack tests, but no avalanches have been reported on this layer, and we expect the recent rain and forecasted temperature drop to eliminate our concern about this layer.
Snowpack depths at treeline are around 120 cm, tapering quickly with elevation. Although the snowpack in most forested areas below treeline remains below threshold depths for avalanches, many steep bluffs, cutbanks, and alpine features in the upper below treeline band are capable of producing avalanches.
Saturday Night
Partly cloudy. No new precipitation expected. Moderate southeast wind. Freezing level rising to 1800 m.
Sunday
Cloudy. 0-5 cm of snow expected, up to 10 cm around Mt. Washington. Snow/rain line around 1000 m. Moderate southeast wind trending to light through the day.
Monday
Cloudy. 2-8 mm of precipitation, snow around Mt. Cain, rain on the southern end of the region. Light southwest wind, increasing to moderate through the day. Snow/rain line around 900 m.
Tuesday
Possible clear periods overnight. Mostly cloudy through the day. 0-3 cm of snow expected. Moderate rain in the south end of the region. Light south winds becoming strong through the day. Freezing around 1000m.
More details can be found in the Mountain Weather Forecast.
