Lawinenlagebericht

Tetons

Bridger-Teton Avalanche Center
Auf der Karte ansehen

Lawinengefahr

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

Kernpunkte

Numerous natural and triggered wind slab avalanches occurred yesterday. Watch for wind drifts in upper elevation and alpine terrain—these will remain touchy and continue to grow in size and distribution throughout the day. Additionally, incoming snowfall today may not bond well to the old snow surface, making avalanches possible on steep slopes that are sheltered from the wind.

Lawinenprobleme

  • Storm Slabs

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

    The onset of snowfall on Monday buried a variable snow surface, in addition to another mid-storm interface from clearing, variable skies yesterday. Temperatures are also expected to warm throughout snowfall today. I observed several avalanches that failed on Monday's interface, and I expect more may fail today with additional snowfall. It will take some time to see how new snow is bonding to old snow and thin crusts formed yesterday and take the time to observe how this interface will behave.

    The takeaway should be that new snowfall will move easily today in steep terrain regardless of exposure to the wind. This will hold particularly true if snowfall amounts end up on the higher end (8-10  inches). If not, expect this to be less of a problem, and expand your options accordingly. Regardless of amounts today, however, loose snow (sluffs) in steep, exposed terrain will continue to pose an additional hazard. Yesterday in the Snake River Range, I observed over 10 loose snow avalanches in consequential terrain and funneled features that certainly bordered on being large avalanches for "just" loose snow. Bear this in mind when choosing terrain today. 

    (3/21/2023)

    Recent activity in the Snake River Range; as the sun poked out, new snow moved easily on many aspects up to 9,200' on the south half of the compass. 

    Photo: Antonioli

  • Wind Slabs

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

    Much of the recent wind slab activity has been observed on the aprons below cliff bands and around rocky, alpine features that drive the wind. Today, expected to encounter slabs in similar areas that may grow in size and distribution today. Drifted areas may still feel like powder, but may have just enough added cohesion that you could trigger a slab avalanche. In addition, yesterday's snowfall was warmed by prolonged clearing and generally has had time to settle into denser, more cohesive snow. Slabs may be sitting atop weak old snow surfaces making them more reactive to your weight. Recognize that wind-loading also adds stress to other recent interfaces buried in the top 50 cm of the snowpack. 

    In most locations, warm temperatures and abundant sunshine last week generated slick crusts that were buried by the ongoing storm. Any slab or sluff you trigger will be able to pick up speed quickly on this crust as it travels downslope. If you head to upper elevation slopes you will find a more complex snowpack underneath the new snow. We haven't seen any activity on weaker snow recently so it is hard to say with confidence how they are behaving during this ongoing storm. 

    (3/22/2023)

    New snow will remain reactive today, with additional slabs building, even in wind-sheltered areas. 

Avalanche Discussion

A long-running winter storm is impacting our region. Don't let the date on the calendar and the long periods of the good old perma-MODERATE danger we've had this year fool you, you'll be dealing with winter conditions out there today. We're looking to see over well over a foot of variable snowfall accumulation from the past 48 hours if this storm produces what is forecasted today. Moderate winds trending in different directions have easily pushed this snow around and built some thick slabs. When the wind blows like this it can build slabs in all sorts of terrain and on slopes where you often find sheltered powder. Be on the lookout for these slabs and be ready to avoid them where they exist. Slabs of new snow will be large enough to bury a person today.

The terrain you play in may change, but your practices, rituals, and systems should stay the same. Enjoy another taste of winter, keep it tight, and take some time to think about the range of hazards you'll be facing today.

Abgedeckte Regionen