Observation Date
1/11/2014
Observer Name
Greg Gagne
Region
Salt Lake » Mill Creek Canyon » Yellow Jacket
Location Name or Route
Yellowjacket Gulch
Weather
Sky
Broken
Wind Direction
West
Wind Speed
Light
Weather Comments
-2C @ trailhead at 0700, -4C @ 9600, +6C @ trailhead at 1200. Some occasional light westerly gusts along ridgeline. Felt more like a tour in March than January.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Wind Crust
Rain-Rime Crust
Damp
Snow Characteristics Comments
Jan 8-10 storms have done wonders for snow depths in Millcreek with several probes showing 75-125 cms. Winds from Friday and warming temps have taken a toll on snow conditions however, with dense slabby snow at the surface. A widespread 1-3 mm rime crust all the way to 9600' on NW/W aspects as well. Was not finding this degree of riming in BCC on Friday morning. Upper elevation westerly ridgelines have lost snow cover due to the strong winds with shrubs now sticking out. Skiing off the west-facing top of Yellowjacket was only finding 10-15 cms of snow on top of old faceted snow.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Rapid Warming
Poor Snowpack Structure
Red Flags Comments
Unsure if the rapid warm up is affecting snow at elevations > 9000'. Did find some debris from wet activity when exiting lower elevations via Porter Fk. Also saw what appears to be the crown of a class 2 slide in upper Alexander Basin. There was a fair amount of debris in the bottom of Depth Hoar Bowl, but the winds have filled in much of everything in upper starting zones, so it was difficult to determine the amount of natural activity that occurred early Friday morning.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
Wind drifts were much less sensitive today, so am thinking public enemy #1 are the various layers of facets now buried 50-150 cms. On Thursday & Friday I was finding a density inversion within the storm snow to be the most reactive weak layer, and several quick pits today were getting CT scores of 5-10, Q2/RP within storm snow. However the past 2 days I was unable to even isolate a column with failures within storm snow, so as often is the case with weaknesses within new snow, they appear to be healing. More of a concern today were the CT10-12 Q1 scores I was getting down 50-60 cms in faceted snow. Storm snow is a 4F (1F where wind-drifted) dense, cohesive slab on top of facets and depth hoar. With snow & wind in the forecast, am expecting this hazard to rise.
Comments
Friday storm was a bust, but the wind seemed to make up for it. If Saturday night/Sunday storm holds together, am expecting the most dangerous avalanche conditions of the season with large slabs on top of buried facets. Avalanches are likely to be very large and destructive.
Fairly poor ski conditions today with dense inverted snow and rime crust. However, with the Jan 8-10 storms providing a very supportable base, am hoping for some fun turns in low angled terrain on Sunday with hopefully lighter densities.
Be safe everyone.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High
