Lawinenlagebericht

Tetons

Bridger-Teton Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
4 · Gross
Waldgrenze
4 · Gross
Unterhalb
3 · Erheblich
Open full map
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Kernpunkte

Intense snowfall and wind have created slabs that will be large and easy to trigger within the new snow. Some avalanches could be very large and destructive, releasing on weak layers deeper in the snowpack. Conditions will be most dangerous on slopes with windblown snow, but triggering a slide breaking 1-2+ feet deep on steep, sheltered slopes is possible.  It will be a good day to stick to lower slope angles. Human-triggered avalanches are very likely; travel in or below avalanche terrain is not recommended today. 

 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    1–2

    Heavy snowfall and strong winds built slabs overnight. Expect to find wind drifts 2-3 feet thick in terrain exposed to the wind throughout the course of the day. These slabs will be easy to trigger today and create avalanches large enough to bury a person. Additional snowfall and wind this morning and into the afternoon will help these slabs grow in size and distribution. Natural avalanches are likely in upper-elevation terrain; pay attention to the terrain above you. Slabs are resting on icy crusts on slopes that directly face the sun. 

    Snowfall rates today are forecasted to be high again (1-2 inches per hour), and conditions will continue to change rapidly. Remember that you may find slopes at low elevations with slabs of snow and extensive drifting. All steep slopes should be on your radar. 

    Avalanche conditions will be most dangerous on slopes with windblown snow, but triggering a slide on steep, sheltered slopes is also likely today.  

    (3/1/2024) Shooting crack that stepped down below the storm slab layer

    Photo: Brian Hunter

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Changing weather means giving slopes with older, weak snow a wide buffer. Weak layers persist in the snowpack beneath hard slabs 3-5 feet deep. Weak snow in the bottom half of the snowpack, now buried so deeply in areas that it has trended dormant, has still produced large natural avalanches in every single storm cycle this winter. Several layers of snow from clearings in February have also persisted in spatially variable ways and continue to cause issues during loading events. Any avalanche involving plenty of new snow today can step down to these deeper layers. Remember slopes that have previously avalanched, as they may avalanche again.   

     

     

    (3/1/2024)

    A recent deep avalanche on Second Pig on Peaked Ridge Grand Targhee 

    Photo: GTSP

Avalanche Discussion

Old Father Winter is back and does not want us to miss our daily dose of snow and wind.  It's not perfectly clear how a buffet of aging weak layers will respond to constant loading and wind. But we do know that natural and human-triggered avalanches will be very likely,  breaking in one of three ways:

  1. Mid-storm instabilities or slides breaking on the old snow surface (now over 1+ feet deep). These slides will likely break in more predictable ways and terrain features, and these issues will be short-lived but very much present today and tomorrow.
  2. Triggering a larger avalanche will most likely be on the interface buried in the top 1-3 feet of the snowpack during the last week of February. These will be more likely on crusted aspects. Newer layers of weaker snow and crusts from a few days of clearing are largely untested, making it more difficult to predict their behavior with the forecasted snowfall. 
  3. While less likely, the added load will make triggering deeper, older weak snow layers possible. Especially in areas with a deeper snowpack, these layers have been showing signs of improvement. It's unclear if they have any punches left in them, but shallow areas that have previously avalanched or weaker snow remain an issue to be regarded. These avalanches would be very dangerous and break deeply. As the new snow continues to add up today, the chances of infrequent and isolated but larger avalanches will increase.

While there is some uncertainty about how our snowpack will react to the impending storm cycle, one thing is clear: the avalanche danger is rising, and we must start traveling more cautiously in the backcountry for the immediate future. This means dialing back slope angles, paying attention to the consequences of going for a ride, and avoiding all wind-loaded terrain. I'll be angling for low-angle "dad pow" with friends today. 

Yesterday, a skier at Jackson Hole Mountain Resort died after falling into a tree well. This is the second snow immersion death in two weeks. Our sincerest condolences go to his friends and family.

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