Avalanche forecast

Togwotee Pass

Bridger-Teton Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
No rating
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Fresh snowfall and moderate winds are forming fresh wind drifts at upper elevations. There's a good chance that your weight could trigger one of these slabs—avoid slopes where you find drifted or pillowed snow. Underneath these drifts, weaker snow buried deeper in the snowpack continues to pose a threat. To reduce your risk, steer clear of slopes where the wind has stiffened the snow surface.

 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Over the past week, the wind has continued to work our snowpack. With clear skies and warmer temperatures, the amount of snow available for transport has depleted. Throughout the day today, reinforcements will arrive in the form of new snow; due to the old, slick surfaces they're forming on, slabs of this new snow could be touchy.

    Up to 8 inches of new snow may accumulate by this afternoon. This snowfall, combined with moderate northerly winds, will form fresh, soft drifts a foot or more thick in upper elevation, exposed terrain. These will be forming on a variety of slippery surfaces including icy crusts and facets, so I would expect them to be easily triggered on steep slopes. You'll want to use extra caution on—or avoid—steep slopes where you find fresh drifts.

    Today's avalanche conditions are directly tied to the weather forecast—which has some uncertainty. If you're finding more than 8 inches of new snow has accumulated, or the winds are blowing harder than forecast, expect the wind slab problem to be more dangerous.

     

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    Early-season persistent weak layers are widespread throughout this zone. In the deeper portions of this zone, these layers are typically found in the bottom half of the snowpack and have been showing better stability. In the middle elevations and shallower areas, the weak snow near the ground is especially pronounced and produced. You're likely to find weak layers near the ground as well as sandwiched between old wind slabs. 

    Triggering a persistent slab avalanche remains possible in terrain with the following characteristics:

    • Steep: slopes in prime-time avalanche terrain around 35-45 degrees.
    • Wind-affected: heavily wind-loaded by past or recent wind events.
    • Alpine flavor: complex, windswept terrain with rock ribs, cliff bands, or convexities.

    ADDITIONAL DISCUSSIONToday's storm is forecast to produce 2-4 inches of new snow in this zone, and this shouldn't have a huge impact on the avalanche danger. The phrase "lipstick on a pig" comes to mind. But with moderate winds expected, look for thin, fresh wind slabs in upper-elevation terrain. These will be forming on a variety of slippery surfaces including icy crusts and facets. So, while small, these could be sensitive to the weight of a skier or rider. 

    (2/11/2023)

    Low elevation pit from Snake River Range shows weak layering; this structure is similar to issues we face at Togwotee Pass.

    Photo: Brenden Cronin

Avalanche Discussion

If you are a regular reader of the forecast, I’d imagine that you are getting tired of hearing about persistent slab problems. Unfortunately, we’ve been dealing with them all season and it is my job to talk to you about them. So drumroll please...any new snowfall means that steeper slopes with weak snow should be approached cautiously. Broadly, at Togwotee Pass over the past several weeks, our attention is slowly shifting from buried persistent weak layers to storm-related surface instabilities. Today's storm is looking to produce up to 4 inches of new snow by the end of the day. With the low-confidence weather forecast, this storm could produce even more (or of course, less). Moderate westerly winds shifting northerly today will easily transport this new snow into fresh, soft wind drifts on upper-elevation ridgelines and other prominent terrain features. These wind slabs will form on old snow surfaces that include anything and everything—wind-hardened surfaces, stiff drifts, sun crusts, and near-surface facets. All of these tend to be slippery, and today's fresh wind slabs will likely be touchy on steep slopes. If the storm produces on the higher end of what is forecasted—say, greater than about 5 inches—we may begin to see a storm slab problem on very slopes that are sheltered from the wind.

It's easy to get cavalier about these surface instabilities after dealing with persistent slab problems all winter. When faced with these "manageable" problems, you may find yourself in consequential terrain where even a small slide can be every bit as dangerous as a persistent slab. Remember that the avalanche danger is only one part of the equation, the other components are your level of exposure to the avalanche hazard and the consequences of triggering a slide in your terrain of choice. Often our overconfidence in managing surface instabilities leads us into the terrain where the exposure and consequences can be dangerously high.

Regions covered