That was a poor weather day, with ATC restrictions in place, so it may not work out, since you need 3 hours of countable events (such as the water and baggage issues). So if BA can say that the delay would 1 hour of weather and 2 hours of handling delays, then they are off the hook. But the rule - in cases of doubt - is always to claim, but that stage the weather wasn't so bad as I recall. Then let us know what BA says.