Skied south of Cooke today and noticed a large natural avalanche just north of the South Siren. N-R2-D2.5-O. It wasn't fresh and likely ran during the last storm cycle.
We dug on an east aspect at 9800', ECTX, HS150. No cr, co.
Observed one avalanche in the steep chutes just outside the N Bridger Bowl boundary, SS-R2-D1-AS
HS between 150 and 200 cm. 90-120 cm of storm snow over firm mid Dec layers over facets. 15cm from the last few days. Some wind transport at mid elevations with lots of W wind up at ridgetop throughout the day. Much windier than expected in Bradley Meadow with moderate winds swirling from N and W. Sky was BKN and, no new snow. Temps around 10F.
As my elevation increased, so did the wind. Heavy gusts were moving snow. Clouds were visible and moving fast above Bridger Bowl and Ross peak. Ross Pass was visibly wind scoured.
I didn’t observe any natural avalanches in the steep terrain along the ridge between ski area northern boundary and Ross peak, but did notice some ski tracks (I believe in the “Trident, Dog Leg chute”).
Observed one avalanche in the steep chutes just outside the N Bridger Bowl boundary, SS-R2-D1-AS
HS between 150 and 200 cm. 90-120 cm of storm snow over firm mid Dec layers over facets. 15cm from the last few days. Some wind transport at mid elevations with lots of W wind up at ridgetop throughout the day. Much windier than expected in Bradley Meadow with moderate winds swirling from N and W. Sky was BKN and, no new snow. Temps around 10F.
We rode into the Taylor Fork today to check out conditions after the new snow from the last two weeks. We traveled up to the weather station above Sunlight Basin, along Sage Basin to the the Beaver Slide, and through Carrot Basin to the wilderness boundary.
No cracking or collapsing was noted today. We did note two small avalanches along the Carrot Basin headwall from sometime in the last two days that broke on weak snow near the ground. These areas looked to have a shallower snowpack. Besides old crowns previously reported, and these two slides, we did not see any new avalanches in the area.
Near Sunlight Basin, we performed a snowpit test on an east aspect at 9480' (HS 98). It propagated (ECTP11) on weak, faceted snow near the ground. Our second pit, at the wilderness boundary, was on a south aspect at 8840' (HS 122). It propagated on weak snow below a melt-freeze crust near the ground (ECTP24).
With blue skies, sunshine, and a lack of cracking and collapsing, it was easy to be lulled into a false sense of confidence about our snowpack. But with a loading event ending only yesterday and our unstable test results, we chose to reign in our enthusiasm, follow a conservative travel plan, and stick to riding lower-angle powder.
No signs on instability on Mt. Ellis. Skinned to the top and descended in the trees to the north of the burn. Ellis does not seem to have the troubling snow structure found in much of the advisory area.
<p>Snow has fallen across the majority of the advisory area all but one day in the last two weeks, adding up to feet of snow and dangerous avalanche conditions (<a href="https://mtavalanche.com/weather/wx-avalanche-log"><span>weather log for specifics</span></a>). Don’t let clearing skies inspire undue confidence in the snowpack. Human-triggered avalanches are likely.</p>
<p>The threat of <strong>persistent slab avalanches</strong> failing on weak layers of sugary facets and feathery surface hoar buried 2-4 feet deep (deeper on wind-loaded slopes) inspires conservative decision-making and cautious route-finding that generally avoids slopes steeper than 30 degrees. Since Friday, the largest two slides we know about failed 600 feet wide in the Lionhead area (<a href="https://mtavalanche.com/node/33361"><span>photos and details</span></a>) and 3-4 feet deep on the shoulder of Sheep Mountain in Cooke City (<a href="https://mtavalanche.com/node/33306"><span>photos and details</span></a>). Go to the <a href="https://mtavalanche.com/avalanche-activity"><strong><span>avalanche log</span></strong></a> on the website to read about nearly two dozen avalanches recorded since Friday. With increasing visibility, we expect to add to the list.</p>
<p>Adhere to the basics of avalanche safety: beacon, shovel, probe, partner and only expose one at a time to steep terrain. If you stray into the peripheries of avalanche terrain, carefully consider the consequences of a potential slide.</p>
<p>The danger is CONSIDERABLE.</p>
<p>The Bridger Range has racked up 44” of snow in the last week, with daily accumulation. <strong>Wind slab avalanches</strong> are the primary problem today.</p>
<p>Yesterday, a skier triggered an avalanche near the ridgeline of South Saddle Peak in the terrain loaded with drifting snow. The slide ran 1500 vertical feet, broke 6” diameter trees and piled debris 20 feet deep (<a href="https://mtavalanche.com/node/33381"><span>details and photos</span></a>). This weekend, a separate slide in Argentina Bowl broke 500 feet wide (<a href="https://www.mtavalanche.com/node/33370"><span>photo and details</span></a>), and skiers triggered a 200-foot-wide wind slab avalanche at the top of the Ramp. (<a href="https://www.mtavalanche.com/node/33322"><span>photo and details</span></a>). Today’s wind patterns in the Bridger Range may deposit unstable slabs in mid and lower-elevation terrain as well as near ridgelines. Avoid wind-loaded slopes by noticing visual clues of drifting, a stiffening of the snow surface and signs of instability, such as recent avalanche activity and shooting cracks.</p>
<p>While we haven’t recorded <strong>persistent slab avalanches </strong>in the Bridger Range, don’t ignore buried weak layers and their threat—continuous loading for more than a week warrants<strong> </strong>careful snowpack assessment evaluating for instability and cautious route finding.</p>
<p>Human-triggered avalanches are likely, and the avalanche danger is CONSIDERABLE.</p>
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
TOMORROW: Wednesday, January 8, 2025, 7-9:30 p.m., Avy Savvy Night at the Colonial Theater, Idaho Falls. More information HERE.
Unsure if Flanders wind is accurate - Rime?
Almost constant Whumphing at higher elevation. I saw a couple of days old avalanche on a wind-loaded east northeast facing slope. This area in known as Yahoo.
