First is driven by the impression of Alonso's heavy accident at the start that was caused by Grosjean and that Alonso luckily survived.
Second are the most exciting weather conditions, that can only be compared to the Nürburgring. If it's not four seasons in one day, it always is good enough for turbulences anyway.
Therefore, let's have a close look on this weekend's weather predicitions for Spa-Francorchamps:
It should became a relaxed practice-day on Friday, unusual fully dry conditions are expected with temperatures of up to 24°C. Being relaxed should only be related to the audience as the teams will already start to fiddle about the wet conditions that are expected right on time for Saturday's Q1. Even if the chance of rain is slighty up above 30 % for Saturday, the rain will intensify ever after Q1 promising a full wet race on Sunday. It's just Ardennes weather.