Forecaster Observation - Tunnel Ridge, Flathead Range

We traveled into Pinnacle Creek/Tunnel Ridge in the Flathead Range to assess the timing of approaching cold front and the subsequent re-freeze of the surface the snow.  Temperatures below 6000 feet dropped below freezing mid-day and started to form a thin crust on the surface.  Above 6000 feet wind exposed slopes were quick to re-freeze. We dug a snow pit at 6000 feet on a northeast aspect and found that the recent warm temperatures and rain had percolated through the entire snow pack where as in a pit at 6700 feet water had only moved through the upper 39 cm (about 16 inches). Stability tests were inconclusive due to the wet pit wall freezing shortly after excavation. We observed widespread recent avalanche activity that occured throughout the week's active weather pattern. Below about 6000 feet most of the activity was loose, wet. Above 6000 feet from a distance we observed several crowns from slab avalanches. There was evidence of recent cornice fall and one very large avalanche on Great Northern that looked like a thick wind slab from early in the week. 

Variable moderate winds with strong gusts blew along the ridgeline with minimal snow transport and drifting. At the upper most elevations where snow was less affected by the recent warm temperatures and rain we could see large plumes of blowing snow.