Lizard-Flathead

Recent storm snow may remain reactive on wind-loaded terrain features and where it sits above crusts.

Moderate - The weather pattern is stable

TUESDAY: Mix of sun and cloud with some light flurries (accumulations of 1-3 cm), moderate west wind, alpine high temperatures near -6 C, freezing level up to 1200 m.WEDNESDAY: Increasing cloud, light to moderate southwest wind, alpine high temperatures near -4 C, freezing level up to 1400 m.THURSDAY: Light flurries with 5-10 cm of snow, moderate southwest wind, alpine high temperatures near -8 C, freezing level at valley bottom.

On Monday, natural avalanches up to size 2 were reported in alpine terrain while skiers and explosives triggered several size 1 avalanches at lower elevations. The 20 cm of new snow was poorly bonding to the crust and produced slab avalanches in wind-affected terrain and loose dry avalanches elsewhere.On Sunday, small loose dry avalanches (size 1) were reported in steep terrain and one size 2 wind slab avalanche was triggered with explosives on a north aspect at 2100 m.On Saturday, a large slab avalanche was triggered in the west of the region. See this MIN post for a photo and more details. A small wind slab avalanche at treeline was also reported.

15-25 cm of snow on Sunday night has fallen above a melt-freeze crust on sunny aspects and all aspects below 1700 m. The new snow has been wind-affected and may take awhile to bond to the crusts.A surface hoar and crust layer buried mid-March is found around treeline at a depth of about 80 cm, with weak surface hoar on northerly aspects and the crust elsewhere. Deeper in the snowpack, the late-November weak layer is composed of sugary facets around a crust, which is buried around 200 to 300 cm deep and is currently dormant.Cornices are large along ridgetops and were actively failing last week.