You hit the nail on the head straight away when you intimated that people would not be easily scared and would have the time and inclination to dress properly. And that would probably apply to both short or longer atmospheric phenomena.
The atmospheric phenomenons could scared easily but it is not enough in this case. This is how I see it:Lightning strike
- scared, could force to leave tent for long time but people are familiar with it so they will dress up and prepare before going to forest. And it usually not happens in winterBall lightning
- scared, could force to leave tent immediately, even by cutting it out, but not last for long so the tent will be accessible shortly after. Even if followed by lightnings they will take some stuff from tent.St. Elmo's fires
- scared, could force to leave tent immediately, even by cutting it out, last long but they should figure it out that it is not as bad as looks like so they will take some stuff from tent.
Not sure if it is possible to have it all together, only in this case they will abandon the tent immediately, without returning for long time.
As well in winter all the atmospheric electrical phenomenons are very rare except St. Elmo's fires.