LOL @ Mark and Billy!
OK then, here goes
[b]Saturday 26 May, from 12 pm
IF the weather is dodgy, More London Riverside
IF the weather is fine for a picnic, Regent's Park (we'll decide exactly where in the park, in due course).[/b]
The above implies us checking the weather forecast and reporting back on to this forum a couple of days before. If it sounds acceptable, I'll start a new, dedicated thread.