Forecaster Observation - Marion/Dickey area, Flathead Range

The first objective for today was to assess wind slab presence/absence and how reactive wind slab were from safe locations along the ridge. The second objective was to assess any storm snow instabilities. Finally, the last objective was to assess how deeper layers (like old, buried surface hoar and/or facets above the late Feb. melt-freeze crust, or facets above any of the more recent crusts (like the 3/6 RC, 3/16 RC, or 3/19 MF crust).

We observed wind loaded slopes on northwest, north, northeast, east, southeast aspects. Winds were strong throughout the day transporting a fair amount of snow. We observed both localized and shooting cracks from the ridge on these slopes. Some wind slabs adjacent to the ridge were rather stubborn when stomping on the top from the ridge, but further down the ridge produced a slab avalanche on an adjacent slope approximately 100 feet wide and 10-14 inches deep.

The avalanche was classified as SS-ASc-R3-D1.5-I. Thus, the avalanche was a soft slab avalanche intentionally triggered by a skier. It was medium size relative to the path, adn could almost bury a person, by could injure a person given the existing trees in the path. The avalanche released at the new/old snow interface. 

The fracture line depth was 10-14 inches and approximately 100 ft wide on a northeast facing slope. The slope was cross-loaded by the wind which at the time was variable, but moving generally from the south. 

We observed both localized and shooting cracks on small, wind loaded test slopes or very small rollovers along the ridge. We did not venture onto any large wind loaded slope. Cornices were very large and growing. Steer clear of these monsters.