The hits keep coming! It's another day to investigate new snow amounts and reactivity before committing to avalanche terrain. Expect the greatest hazard on lee slopes at high elevations.
A 40 cm-deep combo of surface hoar, facets, and crust saw a big test with Saturday's storm. Until we know it's either been cleaned out or capped by crust, be wary of larger triggers like falling cornices or machines in north-facing alpine.
15 - 30 cm of overnight snow should produce a reactive storm slab problem still needing to be managed on Monday. Expect the greatest hazard at higher elevations toward the west Island and where wind has formed deeper accumulations.
Heavy rain Saturday night likely produced a natural wet avalanche cycle. Before the rain took over, ski cutting in the Mt Washington area was yielding wind slab releases up to 20 cm deep in immediate lees on north and east aspects, as well as small dry loose avalanches. Similar conditions can be expected for Monday, minus the high elevation rain.
15 - 30 cm of heavy new snow should accumulate by Monday morning, burying a rain-saturated surface in most areas or 5 - 10 cm of similarly wet snow in the alpine and upper treeline. The new snow should produce short-lived surface instabilities.
A sandwich of surface hoar and faceted snow overlying the late January crust 40 cm deep produced concerning snowpack test results thoughout last week. Crust formation on Sunday should cap this problem almost everywhere, although its status in the alpine is uncertain.
The lower snowpack is well settled.
Sunday Night
Cloudy with wet snow showers bringing 15 - 30 cm of new snow, increasing with elevation, rain below 1000 m. 60 to 80 km/h southwest ridgetop wind. Freezing level 1300 m.
Monday
Partly cloudy with scattered wet flurries in the afternoon, minimal accumulation. 30 to 70 km/h southwest ridgetop wind shifting southeast. Freezing level reaching 1400 m.
Tuesday
A mix of sun and cloud with 5 - 25 cm of heavy new snow from overnight, increasing with elevation and proximity to the west coast. 20 - 30 km/h variable ridgetop wind. Freezing level reaching 1500 m.
Wednesday
Mainly sunny. 50 - 70 km/h southeast ridgetop wind. Freezing level shooting to 2500+ m.
More details can be found in the Mountain Weather Forecast.
