Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
View on map

Avalanche danger

Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 10 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The National Weather Service has issued a Winter Storm Warning through 5 AM on Thursday. In the past 24 hours, the valleys have warmed up 40 to 50 degrees, and the mountains have risen 10 to 20 degrees. This rapid temperature increase is creating unstable avalanche conditions. At 7:45 PM last night, the Cow of the Woods slidepath in Hoback Canyon released naturally and put six to eight feet of snow on the road. Warming temperatures, new snowfall and moderate to strong winds will combine to increase the avalanche hazard at all elevations during the day. As the day progresses, new wind slabs will increase in depth and could be triggered by backcountry travelers or release naturally. At the upper elevations, skiers and riders might be able to trigger a deep persistent slab. Heavy, wet snow along with the possibility of valley rain in the afternoon will also bring about the possibility of wet slides at the lower elevations. Monitor weather conditions and be willing to alter your plans as dangerous avalanche conditions develop.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Moderate to strong southwesterly ridgetop winds in conjunction with new snow will build wind slabs in leeward terrain at all elevations. These slabs are forming on cold, faceted snow on all aspects; and on steep sunlit slopes, the faceted snow is underlain by sun crusts. Skiers and riders could trigger these slabs to depths of one to two feet by this evening. The likelihood of trigger these slides will increase with warming temperatures and new snowfall. Natural activity will be possible, especially later in the day and tonight.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    3

    On westerly through northerly to easterly aspects above 9,000 feet, the likelihood of triggering deep persistent slabs will slowly increase as the storm adds weight to deeply buried weak layers. Large triggers, such as snowmobiles or groups of people, are more likely to be able impact the persistent weaknesses near the base of the snowpack. These hard slabs could have crown depths to six feet.

Avalanche Discussion

Heavy snow is expected overnight and to continue at least into midday. Lighter snowfall is anticipated during the afternoon and evening hours. There could be a mix of rain and snow and or periods of rain at the lowest elevations. Additional accumulations of 6 to 12 inches are expected overnight in the mountains with locally higher amounts. Valleys should get another 4 to 6 inches with locally higher amounts and areas of rain. More snow will accumulate during the day.Temperatures will remain in the 20s at the higher elevations and will be in the upper 20s to mid-30s at the lower elevations. Winds will be from the south to southwest at 25 to 30 with gusts to 45 miles per hour. These conditions will combine to create dangerous avalanche conditions at all elevations. The general avalanche hazard is forecast to increase to HIGH. Travel in avalanche terrain is not recommended when the avalanche hazard is high. Natural avalanche activity is likely and human triggered avalanches are very likely. Wet slides are likely on steep slopes and roof slides are likely at the lower elevations. Large slab avalanches are likely at the mid and upper elevations. This avalanche activity could affect roadways. Due to these conditions an AVALANCHE WARNING will be issued by the Bridger-Teton National Forest Avalanche Center for areas of southeast Idaho and northwestern Wyoming. This warning will be effect for the period from 9 PM tonight until 9 PM tomorrow night.

Regions covered