Observation: Park City Ridgeline

Observation Date
12/1/2019
Observer Name
Zimmerman-Wall/Ghanem
Region
Salt Lake » Park City Ridgeline
Location Name or Route
PC Ridge Line
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Collapsing
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
The October facets are a well advertised issue. We are in for a long period of touchy conditions and judicious inspection of every line facing NW-N-NE-E-SE is going to tell you all you need to know. Discipline is the only answer to this problem.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
Coincident with the Persistent slab, this problem will make even small avalanches a big problem if they gain mass and trigger something larger due to the poor underlying structure. The winds picked up by days end and were moving the snow easily along the highest ridgelines.
Comments
Sunday Funday. Route up the central portion of USA Bowl to Radar Love Bowl and No Name Bowl provided good sight seeing and avalanche viewing. Cold temps at the trail head didn't last long and by noon at 10,000' it was near freezing. Ski quality on shady was 5 star. The wind effected snow was punchy in places and the south facing was perforated by the sage brush and grasses. Structure was right side up and the settled depth was 70cm. Gaining the PC ridgeline, a myriad of crowns dotted the landscape and we bore witness to the aftermath of the natural and human triggered avalanches from the last 72 hours. Collapsing was noted on many slopes on several aspects. Not as prevalent or as deafing as the two days prior, but still noticable.
The natural avalanche on NE facing Scott's Hill was still visible. It wrapped around numerous terrain features and ran to the flats. With the SW wind coming in, this will likely become filled back in quite quickly.
The highlights of the tour were viewing the West Monitor and No Name slides. Seeing the photos from Saturday's obs spurred curiosity, but seeing these avalanches in person was incredible. The No Name Bowl slide was far larger than anticipated. Measurements on Google Earth put this at near 1000' wide and it ran to the aspens in the main run out, and through the pines on the Eastern flanks. The surprising part was just how connected this monster was. It wrapped around several subridge features and pulled up onto the main ridge in places. The fact that this was remotely triggered without from the flats on the ridge is terrifying.
By mid afternoon on the exit out USA bowl, the sun affected snow had gotten quite heavy and tranistioining from shade to sun caused glopping issues on bases. Several pinwheels and roller balls viewed on the drive down canyon.
Photo 1: Radar Love Bowl snow profile
Photo 2: Scotts Hill NE avalanche
Photo 3: No Name Bowl main gut
Photo 4: No Name Slide eastern flanks and debris in trees
Photo 5. Google Earth estimated path
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates