Sign Up for the Utah Snow and Avalanche Workshop (USAW) on December 7th!
Ad
The National Forest Service Logo
icon-add Observation
Forecasts
Logan Ogden Salt Lake Provo Uintas Skyline Moab Abajos Weather Archives How to read the forecast
Observations & Avalanches
Submit Observation Observations Explorer All Observations Avalanches Fatalities Place Names Map Archives
Education
Avalanche Awareness Develop Skills On-Snow Courses Resources and Tutorials
Events
Store
About
Contact Who we are Core Values Staff Board of Directors Past Forecasters Sponsors Annual Reports Sign In
Blog
icon-add Observation
Donate / Join

Observation: Cardiff Fork

Observation Date
2/23/2024
Observer Name
Champion, Antenucci, Jenson
Region
Salt Lake » Big Cottonwood Canyon » Cardiff Fork
Location Name or Route
Days Fork - Cardiff Fork - Mineral Fork
Weather
Sky
Clear
Wind Direction
West
Wind Speed
Light
Weather Comments
It's a beautiful day, generally bluebird with warm temperatures. It was warm in the valley bottoms, but a light breeze kept it manageable most of the day. A few clouds built over the peaks by the afternoon.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Faceted Loose
Melt-Freeze Crust
Damp
Snow Characteristics Comments
Today in the backcountry, we encountered a wide variety of snow surfaces. Starting up the Flagstaff ridge this morning, we found a thin melt-freeze crust on the sunny slopes due to both greenhousing yesterday and some sun exposure. Along the ascent we also found notable preserved graupel mixed within the upper few inches of snow. Once we moved away from the sun-exposed areas, we encountered either cold powder or faceted loose snow. The faceted loose snow was primary preserved to trees and upper elevation northern facing terrain, while upper elevation west facing terrain held just cold powder. Across all aspects, we observed large surface hoar ranging from 1-3mm, with some preserved along ridgetops. As the day progressed, the snow in valley bottoms and on slopes exposed to the sun began to dampen by afternoon. I anticipate a thin, firm crust tomorrow morning on all south-facing aspects at almost all elevations, as well as on western-facing aspects at low and mid-elevations.
Preserved graupel - SW Facing Flagstaff Ridge - 9900'
Noteable surface hoar - up to 3mm in size along ridgelines.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Rapid Warming
Red Flags Comments
Widespread evidence of long-running loose dry or small wet-loose avalanches from the previous day was observed. Some small, loose, dry sluffing occurred when stepping into steeper terrain, but no larger avalanches were witnessed during the tour. However, two larger avalanches (Superior ENE facing terrain and Banana Days) occurred throughout the tour, just moments after we traveled through that terrain or it was out of sight. A few signs of older soft slab avalanches that seemed to have failed on the 2/14 layer were noticed in both Upper Days Fork and Upper Mineral Fork. The snowpack was absorbing a lot of heat by the afternoon, as evidenced by roller balls and pinwheels on the snow surface. We should only expect to see more signs of wet snow as the weekend progresses.
Comments
The main goal for the day was to explore multiple drainages and observe the upper elevations and east-facing terrain in the Days, Cardiff, and Mineral areas. This was the first day in what felt like a week with true widespread visibility. Generally, the east and southeast facing terrain has been the most suspect since the Valentine's facet layer was buried and has now been loaded multiple times. Given the good visibility, it was expected that people would begin to venture out more during their travels.
The primary observation during our travels was the snow surface. As mentioned earlier, there was widespread preserved surface hoar on almost all aspects. Directly below the surface hoar on any solar aspects (S, W, and SE) was a varying degree of supportable crust from the previous day. This now creates another similar interface to the Valentine's Day crust, with a crust and weak snow interface. Given the general weather conditions, I would expect there to be both diurnal facets as well as the potential for some radiation recrystallization facets mixed in on the surface of this crust. Winds remained generally calm, so the surface hoar was preserved even along ridgetops. With continued clear skies and cooler nights, we could see the snow surface above the crust continue to weaken in the following days.
Outside the solar aspects, the snow surface remained generally soft, including a mixture of cold powder, faceted loose snow, and some preserved graupel. This allowed the snow to still run fast and far in steeper terrain, though generally not very cohesive. In colder areas, the new snow still has the potential to knock individuals off their feet and potentially sweep them through more consequential terrain. Areas of increased concern would be those allowing excessive graupel pooling, such as below cliff bands or steep steps, or terrain features that allow for drifting snow to accumulate. Once the wind comes into play, this is where we could have a more cohesive slab.
The final concern is the persistent weak layer, and while we did not observe any recent avalanche activity on this layer during our travels, the snowpack structure still exists. Especially on east-facing terrain that still possesses the crust-facet interface. The likelihood continues to decrease, but as always with persistent weak layers, the consequence remains the same. The weekend's warmer temperatures will continue to influence this persistent weak layer in the right direction, but for the time being, I am going to continue to approach steeper north and west-facing terrain cautiously, and give east and southeast-facing terrain a wider berth.
Solar aspects were beginning to pick up some heat throughout the day, both becoming damp and having widespread rollerballs and pinwheels. This problem will just continue throughout the weekend.
Signs of small loose avalanches from the day prior across from Flagstaff - Toledo
Additonal photo of the Two Dogs avalanche from 2/20 - initially cornice triggered avalanche on a NE aspect
Widespread small rollerballs coming off rock bands - W facing - lower elevation Mineral Fork
Slab avalanche between Mongo No and Barrieto in upper mineral, E NE - appeared to be 1-2' deep failing on valentines day layer.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates