This one was uttered by a work colleague talking about an Andy Kaufman bit that had an audience in “floods of laughter”. It is a mash up of “flood of tears” (crying a lot) and “gales of laughter” (laughing a lot). Not sure if the speaker is from the UK but if so “shakes with laughter” (uncontrollable laughter) might also be in the mix. Certainly gales (strong winds) can be associated with flooding caused by a hurricane. I would much prefer a flood of laughter, however. A big thanks to Matt Whittaker for hearing this one and sending it in.