Observation: Rodeo Ridge

Observation Date
12/14/2019
Observer Name
Derek DeBruin
Region
Ogden » Ben Lomond » Rodeo Ridge
Location Name or Route
Ben Lomond, Rodeo Ridge
Weather
Sky
Overcast
Precipitation
Moderate Snowfall
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
The theme today was rime. Sleet and dense snow in the valley, graupel down low, and rimed forms at the mid and upper elevations. Rime on my car, rime on my skins, rime on the trees, rime on my outerwear, rime on my eyelashes. The theme today was (also) wind. Consistent light to moderate winds down low, sustained moderate winds at the mid elevations, gusting to strong at the least opportune moments. Winds seemed to be from the SW, with occasional changes to the west and even seemingly during south at times. Steady S- to S1 precip down low increasing to S2 at mid elevations, with brief periods of higher intensity.
Snow Characteristics
New Snow Density
Medium
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
Snow didn't quite seem wet enough to call it "high" density. But dense powder up high turned to smooth and creamy down low, making for great turns. Hard to differentiate the current snow from the overnight snow, but I'd give it about 4 inches of "new" snow on average while I was out from about 7am to 1230pm, a bit more higher, a bit less lower.
Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Red Flags Comments
Despite heavy snowfall and clear wind transport in places, hard slabs seemed unwilling to form at mid elevations. Didn't venture to the Chilly Peak ridge line, so can't speak to pillows or cornices up there as visibility was sufficiently limited as to prevent getting eyes on. Surface snow seemed to be holding on reasonably well as little rollovers and test slopes yielded some sluffing, but small at most and quite manageable. In storm slab was attempting to form with the occasional soft block here and there in the surface snow, but no real cracking of any kind that left me concerned things would become sufficiently contiguous to avalanche. That said, I didn't go center punch any steep slopes to disconfirm this notion.
Comments
Dug in on a NW facing slope at 7900ft on the top of the knob. I was definitely in a wind loading zone but was as sheltered as possible without venturing into the truly steep (pit was 30 degrees with 35+ rollovers below). Snow depth almost 1.7m in that location. Snow depth at 6500 feet was 1m, while snow depths in between ranged from 1.1 to 1.4m. Handpit at 6500ft was textbook with P hardness snow on the ground progressing to F snow on top. Pit at 7900 feet featured the bullseye I was after: old snow basal facets from this fall, representing a few to the bottom 25cm of the snowpack. Basically, facets seemed to be as deep as the ground vegetation was tall. Facets were damp and rounding. Above this, right side up the whole way with 1F progressing to F snow. Unsurprisingly, ECT offered no results given the large distance from top to bottom. After this, I cleaned the upper 70cm of snow and did an ECT in the middle of the snowpack at 1m height off the ground, again with no result. Vegetation intrusions in the facets prevented any realistic chance of attempting a PST. Storm interfaces were visible in a few spots within the snowpack, though I couldn't find any surface hoar evidence between layers (could've all been knocked down by wind at this location, though). Shovel shears offered no consistent results. In short, I think things are setting up nicely on Rodeo Ridge and Cutler Ridge, though the basal persistent weak layer still likely warrants a "scary moderate" for a while. Apologies for lack of photos. They were all junk. Despite my efforts, my camera lens rimed almost immediately when I attempted to use it.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable