200/20+ always used to be about the worst wind at LGW - known as Freddie's revenge, due to the proximity of the ex-Laker hangar near the threshold. I remember it well in the B737-200
Having said that, heavy rain and strong winds are rarely associated with cloud bases much below 300 or 400ft with vis less than 800 metres (unless you are at Jersey
), so usually you get a fair stab at the landing with 15 seconds or so to spot it.