Observation April 26
The two of us went our seperate ways on Sunday. I went up to Alta and skied East Castle. Found some wind drifts that were up to 8 inches deep. Because of the previous days warm temps, all the wind drifts found were pretty well welded in place. From the top of East Castle I got a good look into American Fork Canyon. I was only able to find 1 significant avalanche out there. It was in Mill Canyon Peak's "Shaffer Fork Chutes" and was one of the larger point releases I have seen on that peak in quite some time. The avalanche appeared to knock down and burry serveral good sized pine trees and most likely ran because of afternoon heating (making this one easy to avoid).
Troy headed up to Gobblers Knob and skied Cabin Run into Porter Fork. The wind drifts were not as deep as the ones found in the upper Cottonwood Canyons. However a recent Wet Slab that was up to 3 feet deep was observed in Mount Raymonds "Paradise" (a steep north facing bowl inbetween 10,000 and 9,000 feet that is very popular with heli skiers). This Wet Slab was the most likely the result of several days of warming + water running on the rocky bed surface + a cornice fall for a trigger (much like a glide avalanche).
Overall I would call the avalanche danger mostly LOW
for the Wasatch right now. Tonights refreeze will be marginal so an early start to the highest elevations would be a good idea for tomorrow. Because of the Wet Slab seen in Porter Fork I would still say there is an isolated risk (MINY MODERATE)
of triggering one of these "wet slab avalanches" in the low to mid elevation avalanche paths (below 10,000 feet), especially in release zones that have a rocky bed surface. Every year in the Wasatch we usually get full depth wet slab/glide avalanches around late April through mid May in places such as Gobblers Knob (Cabin Run), Mineral Fork (Room of Doom) on the Park City Ridgeline (Scotts Bowl), Stairs Gulch and Broads Fork. With the weather forecast calling for possible snow levels reaching the valley floor later on this week this avalanche concern will likely diminish, until we get another prolonged warm spell.
The 1st picture is close up of the wet slab in Mount Raymond's "Paradise".
The 2nd picture is of Mount Raymond's "Paradise" with the wet slab on the left.