There is a particular type of crash which happens in the wet. A rider will be heading toward a corner, and will start to brake for a corner. At the moment they start to tip the bike into the corner, the front wheel whips out from underneath them almost instantaneously, dumping them on the floor. The crash happens without warning, and without there being anything the rider can do about it. One minute you are up, the next you are on the ground.
The crash happens because on a wet track, grip is unpredictable. Tires cool, and where you thought there was traction, there was in fact none. A tire that might have been working on one side a couple of corners previously has lost so much heat due to the rain, the wind, that the grip you had previously disappears into thin air.
We saw a lot of those crashes in MotoGP FP1 this morning at Aragon, despite clear blue skies and a bone dry track. The reason? The track temperature was simply too cold, and as a result, the tires don't reach the required temperature either. The rubber which is soft and sticky when up to temperature is suddenly stiff and slick as glass, like the tires on a 1:12 Tamiya replica of a MotoGP bike. Johann Zarco and Fabio Quartararo both went down at Turn 14, a notorious point for that particular type of crash to happen.
Down in the dry