Quick report
In the upper elevations, very dense new snow (up to 20%!) and consistently strong winds have created a hard slab about 2-3 feet thick that is sitting on the old snow interface that was buried on 1/31. Good visibility revealed relatively little natural avalanche activity in the area. We noticed one large crown (3+ feet) above Central Couloir and several other smaller crowns (~1ft) on steep features. It’s likely that many avalanches have already been filled in by the wind. It should be noted that many large avalanches were triggered this morning with explosives by the Jackson Hole Ski Patrol.
Ski penetration was only about 2-4” deep, which would explain why human triggering appeared to be stubborn throughout much of the day. However, the large skier triggered avalanche that occurred in Rock Springs North Bowl late this afternoon shows that triggering an avalanche is still possible despite the usual “punchy” or “upside down” warning signs associated with storm/wind instabilities not being obvious.
The snowpack is saturated and mostly cohesionless below 7,500’ from the rain and above freezing temperatures. I noticed 7 or 8 natural avalanches on the Wilson Faces. Several of the debris piles were large enough to bury a person.
No cracking or collapsing was observed in the terrain that we traveled through. Roller balling was observed on low elevation south facing terrain as the day warmed.Weather
- Air Temp
- Upper 20s at 10,000' , warming above freezing below 8,000
- Cloud Cover
- broken
- Wind Loading
- moderate
- Rain Elevation
- 7,500'
- Recent Snowfall
- 9"
- Snow Avail For Transport
- small smounts
Warm and windy today. Periods of sun midday. Terrain below 8,000’ warmed to or above freezing by 1pm.
Snowpack
3 day storm totals at the Raymer study plot (9,300’) are 29 inches of snow containing 4.25 inches of water! The weight that has been added to the snowpack is significant despite the modest snow totals.
Avalanche
- Size
- D2 R3
- Type
- SS
- Count
- 2
- Aspect
- NE
- Trigger
- AS
- Elevation
- 9400 ft
At around 3:15pm a group of seven people were all caught and carried in the North Bowl below Lost Lifty outside the boundary of Jackson Hole Mountain Resort. Six people were grouped together below Lost Lifty on the apron below the cliff band. The seventh person rode slightly above the traverse and triggered a large avalanche that propagated across the slope. All seven people were caught and carried. One person was partially buried with only their ski boot showing. The group arrested in close proximity to one another and were able to perform the rescue and unbury the person quickly. The buried individual's mouth was occluded with snow and sustained injuries. Luckily no other parties or groups were involved. JHMR responded to the incident late in the day and provided assistance in the evacuation. Avalanche danger was rated High across all elevations.