From everything I read there were no weather conditions to cause a tornado, but I could have missed it. The area was covered in snow, although there were rocks beneath, some big rocks but the snow was deep, even at the tent. So whether going out and falling is a possibility, I suppose it could be if there were not enough snow covering the rocks. If you look at the picture of the den built by the hikers, it is about 15 feet deep. I have no idea if they dug that out or they made the den floor and were going to build the snow around it. As far as the ravine 4, they were directly on the bottom with the rocks. At the time of the event, the stream was frozen. From the bodies of the 2 Yuri's and Dyatlov, they were covered in less than 1 foot of snow, so that was 3 weeks after suspected event.
As far as the 2 Yuri's, what was their motive for climbing the tree? Not to get branches because there were plenty at the immediate area. This is a puzzling find. But they definitely climbed because their skin was ripped and there were pieces of their flesh on the tree bark.
The puzzling question about the injuries such as broken ribs, heart bruising, severe head injuries, these type of injuries are not the kind you would find with someone falling down from a standing position. Rustem had fractures on both sides of his temporal areas, one stronger than the other creating a complete fracture to the middle of the suture line. Even if the Ravine 4 fell into the ravine, it had to have been from a tremendous height to incur those injuries. The injuries are comparable to being in a car wreck at a fast speed.