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Observation: Butler Fork

Observation Date
4/5/2024
Observer Name
Hankison
Region
Salt Lake » Big Cottonwood Canyon » Butler Fork
Location Name or Route
Big Cottonwood Canyon
Red Flags
Red Flags
Recent Avalanches
Rapid Warming
Poor Snowpack Structure
Avalanche Problem #1
Problem
Wet Snow
Trend
Decreasing Danger
Problem #1 Comments
2 separate recent (4/2-4/4?) wet slab crowns (~100' & 50') on SE at 8,100' in West Butler Fork with what I'm assuming is the dust layer as the bed surface. Other wet activity were all point releases. The slabs don't have rollerballs that started them, the crowns are clean and near the top of a mid elevation subridge coming off the south summit of Gobbler's Knob.
Undisturbed snow surface in N/NE Butler Trees had almost knee deep boot pen, very wet, almost corn. 5-10cm ski pen until just below ridgeline of Circle Awl where the crust gained strength (5cm) with wet, unconsolidated mush underneath.
Nice to see such a damp snow surface to welcome the incoming storm but very curious to see how many crusts stay intact and curious to see if the dirt layer shows up again after this NW flow.
Photos/description below.
Avalanche Problem #2
Problem
Gliding Snow
Trend
Same
Problem #2 Comments
Glide debris and a large chunk of exposed slab were visible in the Broads Fork drainage (approx Diving Board, NE aspect) from the top of Circle Awl. Couldn't tell the length of the debris field but it looks like it was long enough to cover the common skinner to upper Broads. I think there was an obv already submitted for this one?
Photos/description below.
Comments
Did a lap up Butler Trees in hopes of finding some riding that wasn't covered in crusts or rollerballs. Riding conditions were as good as we could have asked for with the snow surface soft and creamy, trying to be corn. The incoming storm helped keep the surface cool and we didn't find sticky snow until back near the skinner at the base of the run.
I was most intruigued by two wet slab crowns. Most wet slab activity I've seen and read obvs about are caused by point releases, both dry and wet. These are just pure wet slabs, no rocks or trees above them to drop a trigger. Assuming they went natural in the last day or two but the presense of the dirt layer makes me wonder if it was remote, maybe from a long running point release nearby or tree bombs at another place on the slope. I'm guessing the liklihood is higher that they were natural with solar input, though.
Bring on the reset, its a great time of year to be in the Wasatch!
Photo 1: Wet slab crowns, SE @ 8100'
Photo 2: Wet slab debris
Photo 3: Approximate location of these wet slabs, note that it is not shaded on WBskiing app! Good reminder to really keep your head on a swivel for micro-terrain features when wet slabs are lurking.
Photo 4: Long running point release starting in shaded avalanche terrain at 9200' and running down a gully nearly 1000' just to the west of the two wet slabs. This photo shows some rocks near the top of the smaller wet slab crown...maybe a rollerball did trigger it and the larger went sympathetically? Still leaves me with questions about the dirt layer specifically on SE aspects.
Photo 5: Diving Board glide avalanche in Broads Fork
Today's Observed Danger Rating
Low
Tomorrows Estimated Danger Rating
Considerable
Coordinates