February 8, 2021 Knox Creek Avalanche Accident

We are saddened to report an avalanche fatality that occurred on Monday, February 8th, 2021. This is the first avalanche fatality in our forecasting area this season and the 22nd fatality nationally.
Two snow bike riders were caught and buried by a very large avalanche in the mountains west of Salmon la Sac Sno-Park along Cle Elum Lake. One snow biker was partially buried and was able to dig himself out. The other rider was fully buried and killed by the avalanche. The avalanche occurred on a northeast aspect at 4400 ft in the Knox Creek drainage. This terrain lies in NWAC’s East Central forecast zone.
We are actively working with the Kittitas County Sheriff’s office and local Search and Rescue to compile an incident report to be released shortly.
We extend our deepest condolences to the family, friends, and our community.

[@mikemcintosh9933]

My heart goes out to the families affected by this. Thank you NWAC for the information. That 4-6' crown is shocking to behold.

[@stevegriffith22]

Thank you NWAC.

[@landonthings]

Thank you and peace be with the families.

[@ShreddinSleds]

Tragic, this one hit close to home. Thank you for the information. Was there any info on what transponders were used?

[@edearden]

Did you find out if beacons were used here?

[@ShreddinSleds]

@@edearden I haven’t heard anything official, just speculation from close friends

[@vitaminb4869]

By the sounds of it at least one of them didn't have an avalanche transceiver, or it wasn't functioning properly. They were buried very close to each other, any transceiver should have picked up a signal this close. This death could have been avoided.

[@ShreddinSleds]

@@vitaminb4869 that’s exactly what I heard from close sources, it was questionable weather they both had a malfunction or no transceiver at all

[@Ryanbalazs]

Condolences to the victims family🙏🏻🙏🏻

[@PatrickPierceBateman]

The mountains are indifferent to our human suffering.

[@cloud9847]

15' away and would have never found his friend. That's so saddening.

[@bob15479]

These images made me wonder. Is there such a thing as "slope loading" or "cliff loading"? In other words, could snowfall roll down that cliff and make snow deeper right below it, during the storm? That crown seems very thick.

[@danieledmiston1489]

Most likely scenario for that kind of differences in loading is going to be wind transport. Those subtle nooks and crannies in and around the cliff base can modify wind and create deep and shallow pockets of snow.

[@stevepseudonym445]

Really steep slopes are less prone to real avalanches because the snow tends to slough off in tiny avalanches before a lot accumulates, so that's a reason there can be more snow just below a cliff or other steep area. You noticed all that bare rock above the snow slope, right? Besides avalanches (whether small or large), cornice collapse will also dump snow downhill.
What relocates far more snow is wind. That snow largely ends up at a lower elevation but of course it's a completely different mechanism, and rather than simply coming from upslope, it comes from upwind. That can be the other side of the ridge or places that are upslope but in an area where gravity transfer isn't going to happen. There are several reasons that wind loading increases the chances and severity of avalanches. FWIW, all cornices are the result of wind. You won't be able to tell just by looking at a field of snow is it's wind loaded, but with cornices you literally can tell from a mile away. The obvious conclusion is that the slope below the cornice has a lot of wind loaded snow, and the safe bet is that all leeward slopes have wind loaded snow.

[@buttafan4010]

Rebreathers and GPS emergency radio transmitters and loud beeper?