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Observation: Main Porter

Observation Date
12/18/2016
Observer Name
Greg Gagne with Patrice Duvernay
Region
Salt Lake » Mill Creek Canyon » Porter Fork » Main Porter
Location Name or Route
Main Porter Fork
Weather
Sky
Clear
Weather Comments
Bluebird and trace of wind along ridges. Pleasant, comfortably cool mountain temperatures.
Snow Characteristics
Snow Surface Conditions
Powder
Snow Characteristics Comments

Storm slab from Friday has settled somewhat.

Was noticing SH in drainage bottoms, and facets developing at the snow surface. With another clear night ahead of us faceting will continue, and we'll want to watch the current snow surface for continued weakening ahead of hopefully a bit of snow late Tuesday and Wednesday.

Was finding evidence of rain crust up to 8800' in Milcreek. Yesterday in Mineral Fork it only extended to 8500'. Seems warm temperatures and rain prior to the Friday afternoon cold front really took a toll on the lower elevation snowpack where it is currently 45 cms at about 8000' in Millcreek. However, above the rain line, the snowpack quickly goes to 90 cms at 9000', and over a meter above 9000'

Snow Profile
Aspect
North
Elevation
9,300'
Comments

Solid looking snowpack in Main Porter. Was able to identify mid-pack weaknesses in top 60 cms (24") however quality was Q3 with shovel shear. ECTN22 Q3 at a layer of graupel down 35 cms. This layer likely came in at frontal passage mid-afternoon Friday. Otherwise strong, right-side up snowpack that quickly goes from F at the surface, transitioning from 4F to 1F. Shallow 5 cm layer of basal facets that were not responsive to stability tests. Snowpack is looking pretty solid!

Cornice kicks on steep northeast aspect could only produce sluffing in the snow surface.

Based upon what I have seen over this weekend, Moderate hazard (trending towards Low) at upper elevations, with Low at lower and mid elevations. My lingering concern are persistent weaknesses in the top 45 - 60 cms of the snowpack, but from the pits I dug this weekend (at elevations 9500' and below) these layers seem to be strengthening. Cannot get an ECT to propagate, and shear quality at these layers is Q2 or Q3.

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate