Summer Lion Head Trail

Avalanche conditions on the Summer Lion Head Trail were dangerous.  In this location, which is reletively well protected from extreme west and northwest winds, we found a reactive, touchy snowpack that was aligned with the CONSIDERABLE hazard rating at middle elevations today.  Upon approach to the avalanche slope at 4300', we observed a thick, well-connected slab on top of and above the location of the hiking trail. Just a couple of steps onto the open snow slope created long, shooting cracks and a propagating weak layer at the buried melt-freeze crust from January 10th. 

Looking up and across the slope, a crown line was visibile with an estimated depth of 75cm (the general depth down to the 1/10 MfCr).  The avalanche appeared to be about 150 feet wide, though there is a chance it was larger. Our team decided it was not safe to cross the slope and investigate further with hangfire and adjacent slopes around that had not yet avalanched. 

In general, this slope across a popular hiking trail is well-connected and has the ability to produce a large avalanche through the rest of the winter. It's worth noting that avalanches in this area not only have the potential to bury you, but could also sweep you through extremely consequential terrain with trees and cliffs below. 

Long, shooting, propagating cracks were observed on open snow slopes. A recent avalanche was observed on the Summer Lion Head Trail traverse around 4300'. Rapid wind loading was occuring throughout the day and was quickly filling in old crown lines, boot tracks, and test pits.

Above the 1/10 melt-freeze crust, there was new and old wind slab, varying in thickness from 60 - 90cm.  This slab was poor in structure, showing similar strong-over-weak characteristics to an observation in this location on Tuesday, 10/13.  

Two extended column tests yeilded touchy and reactive results.  During the first test, the 90cm column failed upon isolation down 75cm in soft snow on top of the melt-freeze crust. The second test scored an ECTP11 on that same layer.