21-22

Graupel in the Bridgers

Date
Activity
Skiing

On and off graupel falling through the morning. 2-3mm particles. Never more than <1cm/hr

Winds picked up significantly ~1430, predominately NW

Region
Bridger Range
Location (from list)
Texas Meadow
Observer Name
Matt Zia

Decent test on Beehive

Date
Activity
Skiing

Southeast face of Beehive Peak, just below (and to the side) of the exit from 4th of July Couloir -

ECTN, noticed layers approx. 30 and 45 cm down, but couldn't get anything to propagate. 

pit depth approx. 200 cm deep (see buried probes)

felt good about the objective - climbed and skied 4th of July. Glad we did.

Region
Northern Madison
Location (from list)
Beehive Peak
Observer Name
Tom Kochevar

Mission Creek

Date
Activity
Skiing

We turned around about 300’ up the Pitchfork in Mission Creek this morning. There was 10-20 cm thick wind slabs on the margins of the path that I think would have disappeared had we continued higher into what I’ve found in the past to be the more sheltered aspect of the couloir. But we didn’t make it that far after finding a thin graupel layer 60 cm down that was reactive in stability tests. HS was 200 cm where we dug. Hopefully the graupel problem won’t last very long and it’s obviously specific to those sorts of features but I’d imagine it’s present in similar terrain inside the advisory area as well. 

Region
Out of Advisory Area
Observer Name
Henry Coppolillo

Avalanche on Meridian Peak

Meridian Peak
Cooke City
Code
Aspect
NW
Latitude
45.02700
Longitude
-110.00300
Notes

From obs on 2/4/22: "We also observed a fresh avalanche yesterday on the NW aspect of Meridian Peak.  I couldn't discern a crown, due to our vantage point and a low cloud, but the debris pile looked relatively deep, and 12-48 hours fresh." 

Number of slides
1
Number caught
0
Number buried
0
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

From obs (2/4/22): "Touchy surface hoar layer buried under slabs on top of old surface facets in wind protected north and east facing aspects. The layer was observed between 8400 and 9400 feet in the southern Absaroka Range, in Yellowstone National Park. Intentionally skier triggered D1 and D2 slabs 10-30cm thick." Photo: S. Rathbun

Out of Advisory Area, 2022-02-05

GNFAC Avalanche Forecast for Sat Feb 5, 2022

Snowpack and Avalanche Discussion

<p>It is snowing this morning near Cooke City with 3 inches already on the ground at 6 am and another 4-6 inches on the way today. This new snow is falling onto a snowpack with weak layers (surface hoar and near surface facets) buried 12-18 inches down. Skiers yesterday in Yellowstone National Park (outside of the advisory area) intentionally triggered several small avalanches on these layers (<a href="https://www.mtavalanche.com/images/22/avalanche-surface-hoar-ynp"><stro…;). As snow accumulates today it will become possible to trigger larger slides on more slopes. After a long period of relatively stable conditions it’s time to tone back your objectives. Avalanches breaking on these weak layers are often wider than you’d expect and surprise even the most experienced backcountry travelers. The avalanche danger will rise to MODERATE near Cooke City as snow falls today.</p>

<p>The 10” of snow that fell earlier this week has been blown into drifts where you could still trigger an avalanche. Yesterday, in Hyalite several&nbsp; groups of skiers and riders got unstable snowpack test results on weak layers in the upper snowpack and triggered small avalanches in wind-drifted pockets (<a href="https://www.mtavalanche.com/images/22/very-small-wind-slab"><strong><u>…;). With very strong winds overnight expect to find similar conditions again today. Avoid wind drifted pillows and watch for cracks shooting out in front of you as an indication that you’ve found unstable snow and should stay off steep slopes. Triggering avalanches remains possible on wind-loaded slopes where the avalanche danger is MODERATE. On non-windloaded slopes the danger is LOW.</p>

<p>The mountains near West Yellowstone got less snow earlier this week (5-6”). While strongs winds have drifted this snow into cohesive slabs, these slabs will generally be too thin to be a significant hazard. If you find an isolated area with more than a few inches of drifted snow carefully evaluate the snowpack before committing to steep terrain. Large avalanches are unlikely and the avalanche danger is LOW&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

TODAY!  King and Queen of the Ridge at Bridger Bowl.

Good luck to everyone who is hiking and fundraising for the Friends of the Avalanche Center. In the spirit of the Olympics, the trail will be in fast condition and perhaps a new world record will be set!

 

Upcoming Education Opportunities

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming 

Thin and stable conditions

Date
Activity
Snowmobiling

Just wanted to update you on what we found yesterday in the field working on the Frozen Tag.

We rode on the south side of Sawtelle Road below Rae’s Peak and Stamp Meadows Trail and no surprise to anyone we did not find much snow. What snow was there was hero snow with about a foot of loose dry snow on top of a pretty solid base. We did not see or find any signs of instability where we were at. We beat the snow up pretty hard on convex rolls, small wind loads, and short steep slopes with no results.

The biggest concern we found was open streams. A lot of the drainages have few snow bridges in them. But that was really about it.

Region
Island Park
Location (from list)
Reas Peak
Observer Name
Brian DiLenge

Small skier triggered slides in YNP

Out of Advisory Area
Code
HS-ASc-R1-D1
Latitude
44.46360
Longitude
-110.13500
Notes

On Friday (2/4/22), Skiers in Yellowstone National Park (outside our advisory area) intentionally triggered avalanches 4-12" deep on a touchy layer of surface hoar.

Number of slides
3
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
1
D size
1
Weak Layer Grain type
Surface hoar crystals
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From obs (2/4/22): "Touchy surface hoar layer buried under slabs on top of old surface facts in wind protected north and east facing aspects. The layer was observed between 8400 and 9400 feet in the southern Absaroka Range, in Yellowstone National Park. Intentionally skier triggered D1 and D2 slabs 10-30cm thick."

Photo: S. Rathbun

Out of Advisory Area, 2022-02-05