Observation: 10420

Observation Date
2/24/2020
Observer Name
Bruce Tremper
Region
Salt Lake » Big Cottonwood Canyon » 10420
Location Name or Route
Peak 10,420
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Strong
Weather Comments
Cold, post-frontal wind from the northwest remained brisk most of the day. The clouds were puffy, instability cells that occasionally dusted us with a few snowflakes but there were also "sunny breaks" as the Canadians would call them.
Snow Characteristics
New Snow Depth
2"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments
There was only a dusting of about 2 inches of new snow on top of a wide variety of previous snow surfaces--sun crusts on anything sun exposed, wind blasted in upper elevation wind exposed terrain, still some soft, settled powder on straight north facing slopes at mid and upper elevations. These north facing slopes skied OK except that, typical of the Wasatch, after a week without snow, everything was completely tracked up with both ski and snowmobile tracks. We skied a run off the east side dodging perhaps hundreds of old snowmobile and ski tracks, then a couple runs on the north facing trees that also had a surprising number of previous tracks. The upper elevations got heavily blasted by the west and northwest winds overnight creating big snow whales everywhere heavily peppered with copious amounts of fir needles and branches. You had to get well down off the ridges to find some semblance of skiable soft, settled powder in between old tracks and trees. Not a great day for turning but at least it was cold and windy. It was actually a pretty day to be out.
Red Flags
Red Flags
Wind Loading
Red Flags Comments
The nuking, 100 mph winds overnight, plus the much-diminished, yet strong winds today, deposited localized areas of of pre-existing and new snow onto east and southeast facing terrain. Along the summit of Peak 10,420 I found about a foot thick, dense wind slabs on downwind terrain. I jumped on some test slopes along the ridge and found the wind deposits to be stubborn, slabby and sometimes cracky but I could not get any of it to pop out as a slab. The wind slabs were mostly just along the ridges and we got out of them very quickly as we descended the east side of 10,420 where we could easily see the hundreds of old snowmobile and ski tracks from the previous week under 2 inches of new snow. The avalanche danger was mostly low to moderate where I was with a caution to avoid any steep slope with recent wind deposits, which were easy to see and feel from their smooth, rounded shape and slabby, hollow feel. I'm guessing they will settle out fairly quickly.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
None