Quick report
- Red Flags
- Heavy Snowfall, Wind Loading, Poor Snowpack Structure
- Red Flags Comment
- <p>Wind transport appeared limited to the new storm snow. Storm snow was dense — I was able to easily form snowballs from it. It was setting up quickly and made for surfy turns. In steep terrain, graupel was running freely over exposed rock bands above the Highway to Heaven Traverse (see video) and pooling at the bottom of the cliffs. Short term, I’ll be paying close attention to locations where graupel may have pooled and may overload the underlying weak snowpack. While wind loading was front-of-mind, I did not see much transport onto lee slopes at the pass.</p>
Travel was from Alta to Twin Lakes Pass. Aspects skied were N and E facing with slope angles up to about 33 degrees. Moderate to heavy graupel began around 1:30 pm and continued through my exit at approximately 4:15 pm. Estimated precipitation rates were around 1 inch per hour, with roughly 3–3.5 inches of new snow by the end of the tour. Precipitation initially fell as large graupel pellets, painful on bare skin. This phase left a distinct, discolored layer approximately 1 inch thick within the storm snow (see photo).
Snowfall appeared highly elevation dependent. While precipitation was impressive at the elevations I traveled (10,000 ft), snow amounts tapered off quickly as I drove down LCC. Below Snowbird and past the White Pine trailhead, I only observed light sleet with little to no accumulation along the roadway.
Snowpack
- Instability Comment
- <p>I did not observe much wind slab formation in the terrain I traveled, likely due to the sheltering effect of trees along the west face of the pass. In more exposed, upper-elevation terrain, I would expect the potential for sensitive wind slabs given the faceted, weak old snow surface underlying the new snow.</p> <p>I didn't observe any cracking or collapsing today. Not sure if the new water weight is enough to tip the scales?</p>