I’m less optimistic than Sam is about the chances of rain. There is a small shower cell about 40km to the west right now, but the sun is heating up the air and I don’t think it’ll make it to the track because of it. Maybe a few drops around 15:45 local time, but low probability. The even smaller cell he sees to arrive at around 15:05 near the track is already fizzling out. So if there aren’t any humid air masses or intense vertical movement I have missed, this is most probably a dry race. There is some significant gusty wind though.
If I only had better data :). The three weather stations around the track and Lüttich is what I’m working with. It seems that it was more cloudy than I expected and it hasn’t heated up enough. So now the humid air is rising up the mountain and the rain gaining intensity. With any luck we will see some raindrops arriving at 1540-1545.