Observation: West Porter

Observation Date
2/6/2020
Observer Name
Peter Donner
Region
Salt Lake » Mill Creek Canyon » Porter Fork » West Porter
Location Name or Route
West Porter
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Poor Snowpack Structure
Comments
Toured West Porter Monday 2/3 and again today (Thurs 2/6). Toured Peak 9661 from Porter Fork Tues 2/4 and Weds 2/5. Toured all aspects since Monday.
As Greg Gagne reported, West Porter got 2 feet Monday. South off Peak 9661 was about 1 foot Tuesday. West facing Raymond into Mill B North had 6 inches at best Wednesday. Due north descending off 9661 was blower, increasing amounts with elevation loss. At the bottom of the Icebox where it joins Gary’s Gulley at about 8300 feet elevation, there was close to 2 feet Tues which had settled to 18 inches Weds.
Weather today in Porter Fork would be called miserable by those that don’t ski, and by many that do ski. Myself, I toured in my rubberized rain jacket and added a layer underneath as the day progressed. Very wet dense snow and gusty winds. Stayed dry but the blowing wet snow made for a damp chilly experience.
Seemed like there was a natural cycle in the new snow early in the morning producing small D1 slides in the steep southfacing terrain at the entrance to the West Porter path at about 8000 elevation. Bit of cracking in the new snow while breaking trail, nothing alarming.
Skiing in the new snow was challenging, fun if difficult is fun. Best skiing was probably the Porter Fork road. New snow was very dense, less than 6 inches at 9000 feet when I departed at 2pm, but water may be approaching an inch.
On Weds my very experienced partner was taken with the notion of dropping off Mt Raymond into Mill B North, which is an awesome avalanche path ski run. As he was breaking trail he probed w his ski pole finding a rotten snow pack under the pencil hard Sunday 2/2 surface at about 9800 elevation so we bailed. Seems like west facing Raymond has the same issues as west facing Mill B South. My feeling is west/southwest is suspect.
The basic setup for the snowpack is the Sunday 2/2 surface is a generally firm bed surface, the Monday 2/3 storm snow is a weak layer, ranging from 4 inches to 18 inches settled, and the Thurs 2/6 storm snow is a slab, about 6 inches as of Thursday afternoon in wind sheltered upper Porter Fork.
Hazard during the day Thursday seemed low in the low angle wind sheltered terrain I skied. Avalanches seemed somewhere between possible and likely in the steep windloaded terrain. I’m calling the hazard considerable but it may actually have been moderate moving to considerable at 2pm Thurs.
NWS forecast for upper Porter Fork is storm totals approaching 2 feet by 6pm Friday with winds gusting near 30 mph. If this verifies seems like human triggered avalanches in steep windloaded terrain will be somewhere between likely and very likely, so I’m forecasting a high hazard.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High