All elevations in Island Park experienced heavy snowfall combined with high winds,this made for unstable wind slabs and cornices.
Dug a pit and did a ECT. Stayed off of wind-loaded slopes and found phenomenal skiing. On very steep pitches we found some dry loose activity.
We found 175cm of snow
ECTX4@ 168cm
ECTX24@105cm
35 degree slope. 7150 ft
North facing - 10 degrees
Skier caught and carried approx 100 yards thru pinch of main pinnacle chute. Skier was not buried but did lose ski. Suspected culprit of avalanche was cornice drop or skier above sliding down into us. We observed little to no movement or activity before dropping into line besides prior day cornice drop slides. Slide footage can be found @0:55 mark of linked video
https://www.instagram.com/reel/DHZhI6DMGse/?igsh=YWgxd3cyaGpzY3F5
It looked like there were several small wind slabs triggered on Saddle Peak. I was skiing with my family and didnt get a good look or a photo. One appeared to be just off the summit maybe 12" deep and not running very far at all. The other appeared to be near the going home chute even with the cliffs, and this one ran a bit further. These wind slabs looked like something to be looking for but also easy to avoid.
We were split boarding south of Cooke City today, up to terrain around 10'000', and finding good snow stability.
Weather was mostly cloudy in the am, partly cloudy in pm. Light winds from the SW.
No fresh avalanche activity observed. Attached is a photo of the only sign of a recent avalanche we could find. (an old crown on an East aspect at 9600').
<p><span><span><span><span><span><span>Snow totals from the weekend storm range from 24-46 inches of snow containing 2.3-4.8 inches of water. Many slopes have a deep, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34679"><span><span><span><span><span><… snowpack and good stability</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, BUT not all. There are two main avalanche problems, one is easy to avoid while the other is more tricky. </span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Heavy snowfall and ferocious winds formed large wind slabs </span></span></strong></span></span></span><span><span><span><span><span><span>last weekend and early this week</span></span></span></span></span></span><span><span><span><strong><span><span>. </span></span></strong></span></span></span><span><span><span><span><span><span>While these wind slabs may have stabilized some the last two days, more wind and snow will load the same slopes today keeping them on edge. </span></span></span></span></span></span><span><span><span><strong><span><span>These wind slabs can be quite large</span></span></strong></span></span></span><span><span><span><span><span><span> and mostly an issue at upper elevations above treeline. Several great examples of this problem were avalanches spotted yesterday north of Cooke City </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34685"><span><span><span><span><span><… Wolverine Peak and Scotch Bonnet</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34690"><span><span><span><span><span><… Goose Lake</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The load of such </span></span></span></span></span></span><span><span><span><strong><span><span>heavy snowfall has also awakened a persistent slab avalanche problem</span></span></strong></span></span></span><span><span><span><span><span><span>, but this one is </span></span></span></span></span></span><span><span><span><strong><span><span>really tricky</span></span></strong></span></span></span><span><span><span><span><span><span>. Slopes with a relatively thinner snowpack still harbor weak, faceted snow and can produce avalanches like </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34684"><span><span><span><span><span><… in Sunlight Basin</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> in the southern Madison Range yesterday. Some areas may have a thinner snowpack overall and will be easy to identify by digging a snowpit. Other areas will have isolated slopes with a thinner snowpack because they either previously avalanched or were scoured by winds at another time.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Today wind loaded slopes (loaded last weekend and being loaded again today) have a CONSIDERABLE avalanche danger. Slopes not loaded by winds have a MODERATE danger, but this is tricky. Riding slopes less than 30 degrees in steepness that aren’t steep enough to slide is always a great option.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The mountains near Bozeman and Big Sky have a strong deep snowpack, and the single avalanche problem is </span></span></span></span></span></span><span><span><span><strong><span><span>wind slab avalanches</span></span></strong></span></span></span><span><span><span><span><span><span>. Ski patrols triggered wind slabs 6-12 inches deep yesterday. While skiing at Bridger Bowl yesterday, I thought I could see several small wind </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34696"><span><span><span><span><span><… triggered on Saddle Peak</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, one at the top and one maybe halfway down.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Winds increased again this morning</span></span></strong></span></span></span><span><span><span><span><span><span> from the W and SW. They should be moving more snow today, building new wind slabs and keeping older ones on edge. As Ian found </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34666"><span><span><span><span><span><… the Throne in the Bridgers on Tuesday</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, the simplest option for good skiing and riding as well as good stability is to </span></span></span></span></span></span><span><span><span><strong><span><span>ride slopes sheltered from the wind</span></span></strong></span></span></span><span><span><span><span><span><span>. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Today with a little bit of snow falling and strong winds blowing, the avalanche danger will be CONSIDERABLE on wind loaded slopes. Getting out of the wind will be a challenge, but slopes sheltered from the wind with no wind deposited snow will have good stability and a LOW danger.</span></span></span></span></span></span></p>
Today we saw a D2 slab avalanche at Goose Lake, E facing, 10800 ft. We estimate this avalanche to have ran in the early hours of 3/17. This was the only avalanche we observed in the past 4 days.
We rode the motorized zone today with Bill and noticed two slides. One on the SE face of Scotch Bonnet in Tragenic Bowl and one on the NE face of Wolverine. They both broke 2-4’ deep. The avalanche on Wolverine slide aprx 1500’. Both were in wind loaded areas at upper elevations. Ski cuts with snowmobiles were not producing avalanches in protected areas.
From FB message. Today (3/19) in Taylor Fork
It looked like there were several small wind slabs triggered on Saddle Peak. I was skiing with my family and didnt get a good look or a photo. One appeared to be just off the summit maybe 12" deep and not running very far at all. The other appeared to be near the going home chute even with the cliffs, and this one ran a bit further. These wind slabs looked like something to be looking for but also easy to avoid.
