Red Flags-a-Flyin'

On Saturday, a trusted observer alerted us to a reactive layer of buried surface hoar responsible for unique snowpit test results and a skier triggered slide. I grabbed FAC Professional Observer Guy Zoellner, and off we went in search of the mythical ECTP 1.

• Recent avalanche activity is a red flag of the highest order, and we eliminated areas adjacent to the triggered slope from today's run list.
• On the ascent, numerous hand pits at mid and upper-elevations revealed a clean failure in a buried layer of surface hoar capping the 1/13 crust (red flag #2).  
• Before we reached the ridge, solar warming initiated numerous rollerballs on steep slopes open to the sun (red flag #3).
• The warming aided in forming a surface slab in previously cohesionless snow (red flag #4).
• A pit on a south aspect showed us that the surface hoar had survived on solar aspects above 7100'. This layer's identification tells us that the Persistent Slab structure is found on most aspects at this location (red flag #5).
• Our pit on an east aspect at 7200' revealed two obvious layers of buried surface hoar in the pack's top 2'. Snowpit test results of ECTP 3 (top layer) and ECTP 14 (lower layer) confirmed its reactivity (red flag #6). 
• The slope we ruled out for today's descent released as a slab avalanche on the uppermost layer of surface hoar while we were conducting snowpit tests (red flag #1, all over again). 
• We enjoyed watching a wet loose slide with a head of steam entrain snow on the same face (red flag #3, again).

Red flag #1 was more than enough information for us to dial our terrain selection way back. The other red flags confirmed that we needed to identify slope angle and shape for a successful powder run.