Skiers in the Love Chutes triggered this avalanche after a ski cut produced no results. Further down the chute, the first skier triggered an 18" wind slab avalanche. They were carried 200' before self-arresting and were uninjured. Photo: Anonymous
23-24
Wet avalanches in Island Park
From IG mesasge (4/6): "Some wet action at arange peak near Sawtell yesterday. From slope Dave and I did our first pit on Monday. Lots of release in that new old interface but didn’t see anything releasing down deeper."
Fairy Lake Obs Sunday 20240407
From email: "Riding was good - deeper than anticipated, though maybe not worth the damage and mud on the way out.
There were plenty of signs of storm snow instability, especially in the wind loaded terrain. Didn’t really need to dig to be on alert. We kept the angles relatively low all day, plenty of fun pow to ride in the trees. "
Riders also noted a human-triggered avalanche on the shoulder of Hollywood Bowl
New Snow Avalanches in the Bridgers
We toured up the Ramp today from the Bradley's Meadow backcountry gate. Near Bradley's we measured 19" of snow and 2.7" of snow water equivalent. On several test slopes, we observed cracking and only triggered small sloughs in steep pockets of terrain. At noon we stopped above the refrigerator chutes and dug there. We found 24" on new snow with 3.05" of snow-water equivalent. In the storm snow, we had ECTP6, ECTN11 & PST24/100 SF. Below the recent storm snow was a 1.5" thick crust with moist snow beneath.
Near the top of the Ramp we saw a small skier-triggered avalanche that buried a portion of the skin track in front of us. While skiing down the ramp new snow was easily sloughed but never picked up much momentum. On our second lap, we saw several skier-triggered storm slab avalanches breaking ~1' deep within the new snow (R2/D1.5). We saw one larger avalanche below the cliffs between the Refrigerator Chutes and Wolverine Cirque (R2/D2). We spoke to a skier who skied Wolverine Crique who reported many small storm slab or slough avalanches. All of these avalanches occurred on slopes steeper than 35 degrees.
Snow continued in strong pulses throughout the day and we estimated 2-3" fell between 12:00 and 2:30 pm. At the top of the ridge, winds were light from the south. At the middle and lower elevations, winds were moderate with strong gusts. Bradley's Meadow back to the parking lot was very wind-affected.
Small, Skier-triggered avalanche at the Throne
A skier triggered a small avalanche on a steep north-facing pitch, but it did not run far. We saw limited cracking on a layer within the new snow generally 4" to 1 foot deep, and got an ECTP11 on this layer in one of our pits on the east-facing pitch near the standard ski track. Our other pits, one lower on the east face and to the north of the saddle at the top of the Throne, resulted in ECTNs between 5 and 15 on this layer within the new snow.
A skier triggered a small avalanche on a steep north-facing pitch at the Throne, but it did not run far. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Mon Apr 8, 2024
Mt Ellis Observation
Roughly 2 inches of new snow in the parking lot at Bear Canyon. Up high on the top of Mt Ellis at 8300 feet there was 6 to 8 inches. Did a column test and it broke on the new snow layer above the crust about 23 cm down from the top at 3 taps from the elbow. Then we kept going and got it to fail at the weak layer near the bottom of the snowpack at 6 taps from the shoulder.
Storm Snow Instability
We traveled into the Throne on a snow-covered road, but unfortunately, by the time we came out at the end of the day, it was a couple of miles of off-and-on mud. I can't really see how the road will last beyond the end of the snowstorm for snowmobiling. By the time we turned off the road for the final ascent to the sled boundary, there was a foot of new snow, and by the top of the Throne, over two feet of new snow equal to 2.5" SWE.
There was a thick, supportable crust below the new snow, and our primary concern was instability within the new snow and on wind-loaded slopes. A skier triggered a small avalanche on a steep north-facing pitch, but it did not run far. We saw limited cracking on a layer within the new snow generally 4" to 1 foot deep, and got an ECTP11 on this layer in one of our pits on the east-facing pitch near the standard ski track. Our other pits, one lower on the east face and to the north of the saddle at the top of the Throne, resulted in ECTNs between 5 and 15 on this layer within the new snow. While there was some limited wind transport of the new snow, we did not find any slopes that I would define as wind-loaded to test instability. My educated assumption is that you could trigger a large avalanche on a wind-loaded slope right now.
While we traveled in and skied avalanche terrain, we stuck to the lower-angle end of the spectrum and selected simple slopes with fewer terrain traps.
The new snow will provide fresh ammunition for wet, loose avalanches as the temperatures warm this week.