Snow Observations List

Yesterday 4/25, Walked to the top of Pierre's Knob. The snow was unconsolidated mush, very sticky skiing. While hanging out at the top shack I heard 3 large avalanches running in the south bowl, white out conditions so was unable to see how big the slides were they sounded like they ran a long ways.

On 4/22 at 12:30pm we were part way up the boot pack (now skin track) up from Bridger chair to the ridge. We heard someone yelling and looked over to see a skier caught in an avalanche just above North Bowl Road. The slide came to a stop at the road (they were on top the whole time), and the skier yelled that they were ok. Seemed like they were skiing alone but more of the party may have been out of view. We had not seen wet snow concerns until about 30 minutes before the incident. By the time we left bridger, most chutes had slides out of them.

Our party toured into Beehive on Saturday. There was about 20-25 inches of new snow on our approach in.

We dug a pit at approx. 8,700 ft on a S aspect. Our 280cm probe couldn’t reach the bottom of the snowpack, it was the most snow we’d seen in the zone. There was 60cm (24in) of new snow that was perfectly bonded the the crust layer below. The next 60cm below this was a mix of 1f to P hard melt-freeze crusts that showed now signs of instability.

Our extended column test resulted in an ECTX and showed nothing but stability within the new snow. We reached the summit and skied the S ramp of 10,602, it was deep. As we exited the basin there was significant warming that had taken place at lower elevations but no signs of instability yet.

Spent the day choking on DEEP snow in the meadows around Fairy Lake. Light to mod. showers all day with a brief lull around 330 which allowed a window of visibility into the upper elevation terrain: No slab avalanches observed which surprised me (hence the obs.), very minimal loose snow moving despite the impressive SWE totals. Some wind texture at upper elevations but the new snow appears to be settling out quickly in typical April fashion. 

At 5pm on 4/20/23 I dug a quick snowpit to look at the storm snow o the Bridger Ridge. at 8,400’ there was 36” of settled snow equal to 3.6” SWE from the last two days. Total depth was 311cm (~10’ 3”).

No cracking or easy triggered loose snow on small test slopes. Surface was getting more slab-like or cohesive. In general the snow was more stable than yesterday, but there was a ton of snow so still potential for big avalanches. Probably less frequent than the recent dry loose snow activity, but potential for larger slab avalanches or wet avalanches.

Stability of the new snow could become worse if wind increases and drifts the snow into dense slabs, or when warm temperatures and sunshine arrive later in the weekend and make the snow wet and weak. 

20-36" of low to medium density snow in beehive, bear, and middle basins.  Moderate west winds and overcast skies. It snowed lightly all day and the sun never came out.

We skied south, east, and west aspects. Snow was mostly right side up and was unconsolidated. Sluffs were running on steeper terrain, but other than that, we didn't experience any reactivity or signs of unstable snow.

By early afternoon on 4/19/23 the three feet of new snow was easily avalanching and running long distances with large volume. Video from Test Face/Lower Nose.

At 6pm, 4.19.23, the Bridger Range has received 37" of new snow in the last 20 hrs (29" were measured at the top of Bridger when the snow board was cleared at 1pm, and 8.5" have fallen since) equal to 2.2" of snow water equivalent (measured at Alpine weather station).

I skied up and down under the Bridger lift between 10am and 2pm. The new snow slid easily on steep slopes, mostly dry loose avalanches, but by the afternoon these were entraining large, dangerous volumes of snow. Video is from this morning, small test slope at 6,300', north facing. Now there is a lot more snow, and much more at higher elevations. It snowed heavily all day. Wind was moderate on the ridge, calm with moderate gusts below the ridge, and moderate/gusty on the lower half of the mountain. 

Large avalanches of new snow will be easy to trigger for the next few days, and large natural avalanches are possible. Conditions will continue to become more dangerous if heavy snow continues.

We observed a large slide at the Apron that was released from the Hidden Gully. In a whiteout, we couldn't tell the size, but it looked quite substantial. The slide didn't go all the way to the bottom.

New snow is not bonding well to the old snow surface.  Sluffing and running far on steeper terrain.  Photo taken on First Finger. Heavy snowfall and wind.

Had some loose wet slides on the fin today just after noon. Was about 3-6” deep at the new/old snow interface. Slide was slow moving but carried farther than we thought. 

Usual spring conditions. Out farming corn snow. Saw some activity from the warming sun.

Observed evidence of natural slide activity yesterday while snowmobiling Buck Ridge. First pics are on a northerly aspect off Sphinx near the wilderness boundary, second set of pics are south facing off Pioneer Mtn.

Approx coordinates of slide #1: 45.15872, -111.46923

Approx coordinates of slide #2: 45.22781, -111.46531

Was able to spot a deep slab avalanche from Gallatin peak, slab was at the headwaters of S Fork Hellroaring (N aspect @ 9800) Hard to tell when this released as it was a few miles away, I would estimate the crown being around 10 feet. Observed a small storm slab on a north aspect as well (1-2 foot crown). Also saw a few dozen wet slides that released earlier this week, some tearing all the way to the ground. 

This afternoon my group triggered a dry-loose avalanche on the north face of Big Timber Peak in the Crazies. The slide was about 12 inches deep, 50 feet wide, and ran about 1,000 vertical feet. Thankfully, no one was injured. We didn’t officially measure the slope angle but we’re estimating it to be in the 38-degree zone—prime avalanche territory. The slide consisted of new snow that fell during this recent storm. It hadn’t bonded to the thick crust underneath and released during the second skier’s run.

While skinning into Big Bear gulch, off Wisconsin creek, we encountered a couple of small whumphs in a flat meadow below treeline. We also encountered one instance of localized cracking within the trees, near the hollow created by a dead tree. At the top of the ridgeline there were small cornices, and we noticed significant wind loading higher up on Old Baldy mountain.

In our east facing pit, just below the Little Bear ridgeline, we found a large melt freeze crust complex near the surface, interspersed with layers of much softer snow and NSF. Below the stout crust layers, the snowpack drastically reduced in hardness, with fist hardness facets near 50cm from the ground. We had moderate CT results (CT 12 Q2 @140cm) within the crust complex, and more difficult CT results (CT 23 Q2 @30cm) within a layer of large (3mm) striated depth hoar near the ground. Our ECT test resulted in an ECTX, possibly indicating the strength of the crusts, which neither skis nor boots would penetrate through. Our ECT column did pull out of the wall as a cohesive block when we applied shear from behind. Our pit profile was submitted through Snowpilot.

Based on these observations, and the warming we believed would occur later in the day, we decided to not ski off of Old Baldy mountain, and rather took some laps at a nearby low-angle meadow. 

Pretty much the entire wall skiers right of the prayer flags back into beehive slid. Wet slide. Multiple crown lines and long running. 

Photo from IG 4/13/23: @waxeman

Small storm slab off the steep drift on skier's R/skinner's L side of upper Thunder Road. Also felt some cracking and collapsing when I (briefly) stepped off the skin track to get to the top of Pierre's Knob. 

skinned up to the ridge and observed 5-9 inches of new and accumulating snow forming into wind drifts that were highly reactive. Multiple remote triggers occurred while traveling N on the ridge, propagating  both on W and E faces of the ridge. Both Hidden and Northwest Passage slid with little effort down to an icy bed surface. Debris at bottom of hidden was substantial but great skiing.