PTF wrote:
No...as far as the runners are concerned...the wind is not blocked by buildings. Since the wind is predominately at the runners back it will be quite strong in the middle of the road where it is relatively unobstructed. Wind behaves much like a flowing river...taking the path of least resistance.
In this case, where the wind is following the direction of the road so closely, the buildings on either side can almost make the wind in the middle of the road stronger as it becomes almost like a wind tunnel.
But you won't see much wind reflected on those flags that are a few feet directly downwind of a brick building.
If that were the case, then shouldn't that first flag be moving quite a bit. There's nothing around it. Second flag is definatley hidden by the buildings. But the third flag is doing exactly what Malmo's picture suggest is should do, and that's going to the side more than anything else. So really, the picture and the video are doing exactly what my original post said. The wind helps/hurts the runners based on where they were on the course, what direction the wind was at the time, and what buildings, etc. were in the way to disrupt the natural flow. Which brings me all the way back to the fact that there is no way the runners had a 20mph tailwind the entire way. And we've proved it. I WIN!!!!!