If you wanted a demonstration of just why the weather at Sepang can play such a decisive factor, you need look no further than MotoGP FP2. Fifteen minutes before the MotoGP bikes were set to take to the track, the Moto3 machines were finishing their second free practice session in sunshine and sweltering heat.
But a couple of minutes before MotoGP FP2 was meant to start, the heavens opened, producing a deluge that had first-time visitors to Malaysia hunting around for gopher wood with which to build a boat.
The downpour covered the track in several centimeters of standing water, making it impossible to ride. The session was delayed for twenty five minutes, starting after the rain had nearly eased up completely. Once the session got underway, the weather cleared up completely, the last ten minutes taking place in glorious sunshine once again.
The changes in the weather had a dramatic effect on the state of the track. It went from being fully wet, with water everywhere, to having just a thin layer of rainwater on it at the halfway mark, to being dry at most of the corners around the track once the session ended. Full wets were essential at the start of the session, but forty five minutes later, slicks were starting to become a viable option.