Observation: Porter Fork

Observation Date
1/2/2019
Observer Name
Greg Gagne
Region
Salt Lake » Mill Creek Canyon » Porter Fork
Location Name or Route
West/Main Porter & Mill B South
Weather
Sky
Clear
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
NW winds picked up along ridges in the afternoon. Some plumes off of upper elevation ridges, but likely sublimating.
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Wind Crust
Damp
Snow Characteristics Comments
Some steep, southerly aspects likely crusted on Thursday morning. Surface is weakening with NSF, SH as well as some radiation recrystallization (RR) on isolated solar aspects facing S and SW.
Haven't been in to Porter in 2+weeks, and was finding a thinner, more faceted snowpack when I was last in there, but it looks much more stable than before with HS exceeding 90 cms above 8500'
Wind drifts from 12/31 wind event are unreactive to stability tests.
Comments
Overall stable snowpack found in Porter Fork. Several quick pits today and no columns propagated on any ECTs. Shears were all Q3 poor quality. In north aspects > 9000' there was some October facets, but they are gaining strength are now are 4F+/1F. All snowpacks I looked at had rightside-up structure with F -> 4F -> 1F. Also looked at southerly aspects as there have been reports of facets atop old sun crusts. I was finding a 5 cm faceted layer on top of an old, mid-December crust, but not reactive. Photos are of different pits showing overall stable snowpack:
In thinner snowpack areas I have looked at the past several days, I am finding the weakest snow to be down 30-45 cms. This is just underneath a 1F 5-10 cms denser slab that formed in the middle of December, prior to the onset of consistent storms in 12/19. The week prior had been warm with a few wind events, creating this denser slab. Underneath this slab is weaker, faceted snow. In thinner snowpack areas (thinner = < 90 cms) these facets are weakening due to the strong temperature gradient. Right now this is not a concern, may may be so once we get additional loading.
Currently, in thicker snowpack areas, the snowpack is still strong, with the weakest snow at the surface.
Photos of some 1-2 mm facets in thinner snowpack areas. (Photos are manipulated to highlight the squares.)
Overall hazard is generally Low. Wind drifts from 12/31 NE/E wind event are unreactive, but I imagine there are some pockets at the upper elevations where they may still be reactive to a rider. Hazard definitely trending to Low.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate