Glassing Hwy 75

This was a short, late afternoon driving tour to look for wet snow activity. 

No direct snowpack observations. Plumes of snow from moderate speed northerly winds were periodically visible throughout the Sawtooths in the afternoon. I observed a fair amount of small wet loose activity from the previous two days, but this was not widespread. Lots of small dribbles and swarms of rollerballs but most of these did not gain much mass. I could see evidence of larger slides in steep rocky terrain, but I could not see debris piles in these locations (S on Parks at middle elevations, S on Imogene at middle elevations, S on Heyburn at upper and middle elevations, etc). Many surfaces in the Sawtooths and Headwaters areas had a thin, reflective coat of water ice at the surface (firnspiegel), indicating that snow surfaces have been staying relatively cool and quickly refreezing despite the intense solar input. 

Solars have multiple crusts (with associated facets) in the upper and middle snowpack. With significant warming and water input there is a worrisome chance for much larger slides to release on these layers. Cool temperatures and steady winds have helped to keep snow surfaces cool, but we are looking at calmer, warmer conditions through the weekend and I'm expecting to see wet problems become worse. Strong southerly winds blew during the previous few weeks of precip deposition, with a wind switch to N/NE on Wednesday. These winds took care of much of the loose snow sitting around at the surface making large wet loose slides a bit tougher to initiate. 

General consensus is that we haven't quite got to conditions for widespread natural wet avalanche activity, but human-triggered avalanches have been easy to make during the heat of the day. We are in a diurnal pattern of avalanche hazard, with the likelihood of triggering large avalanches increasing significantly during the heat of the day. If we see overnight temps hovering around freezing and much warmer daytime highs this obvious pattern may become much more complex as meltwater percolates down to and wets deeper layers.