Lawinenlagebericht

Togwotee Pass

Bridger-Teton Avalanche Center
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Lawinengefahr

Fri
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
Keine Stufe
Open full map
Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Increased wind out of the southwest combined with periods of rapid snowfall will create dangerous avalanche conditions in the upper elevations. Human triggered avalanches will most likely be on slopes where you encounter obvious signs of wind drifted snow such as cracking, stiffened surfaces, and large pillows. Avalanche danger will also increase throughout the day with additional snowfall and continued wind.

Lawinenprobleme

  • Wind Slabs

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

    Wind increased yesterday to 10-20 mph continuing today out of the southwest forming fresh slabs 1-2 feet deep with the low density snow that is available for transport. In addition, continued snowfall today could reach rates of an inch or more per hour adding up to 7” of snow by this afternoon. The combination of increased wind and rapid loading will create fairly widespread new snow instability in the upper elevations. Look for open and exposed terrain in the middle and upper elevations where the snow has been drifted by wind forming stiffened surfaces, pillows and dunes. Avoid wind loaded terrain and remember that cracking snow surfaces is a clear sign of unstable snow. 

    (3/14/2024)

    Cracking snow surfaces, a sign of instability and wind loaded terrain. 

    Photo: Alex Drinkard

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    Triggering an avalanche remains possible on weak snow buried 2-4 feet deep below hard slabs. This weak, sugary snow exists across all elevations and most aspects near the base of the snowpack. Wind loaded slopes will be the biggest concern today, as triggering a wind slab has the potential to step down to these deeper weak layers initiating a much larger avalanche. Overall persistent slab avalanches are difficult to predict, but areas where triggering is most probable include steep, rocky, and wind affected slopes on the north half of the compass. These slopes contain thin, shallow spots where riders can impact the weak layers more easily.  

    The last persistent slab avalanche occurred 3/16 in Upper Deception Creek. A wet slab avalanche failing on these persitent weak layers occured 3/19 on Breccia.

    (3/17/2024)

    A snowmobile triggered persistent slab avalanche.

Avalanche Discussion

Winter continues...

The snow has been stacking up throughout the week with 16” of snow and 1.44” of snow water equivalent at Brooks weather station. A Pacific trough and cold front brings a winter weather advisory to Togwotee today. Wind began to increase yesterday in the morning/afternoon (293 total miles of wind in the last 24 hours at Lava weather station). Visible wind transport of snow was observed yesterday in the upper elevations. Snow that has fallen throughout the last week has remained low density and easy to transport by the wind. Combine this with rapid snowfall rates today and we will see increased avalanche danger. The snow that fell this week sits on a fairly widespread crust on W-S-E aspects, with small facets developing around the crusts. Facet development on northerly aspects has been spatially variable, but most prominant in terrain sheltered from the wind. Recent snow has slowly been gaining strength on these poor interfaces. Keep this in mind as additional loading stresses this interface. Performing quick hand shear tests and assessing any recent snow instability will be critical while traveling in the mountains. Pay attention to changing conditions today as fresh wind slabs continue to form throughout the day. We’ve had fairly stable conditions throughout the last couple weeks, so don’t become complacent to increased danger today. Seek slopes sheltered from the wind and enjoy the fresh powder riding. 

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