Again, not all the mañaina said this, but some people have told me they heard it growing up :
An duru i ichan, maolek, sa' pinino' i manglo'.
(When it rains hard, it's good, because it kills the wind.)
The idea was that the rain stopped the wind from picking up, thus preventing a typhoon, which nobody ever wants.
At the same time, other people told me a different version :
An duru i hilu, yan tettete i ichan, maolek, sa' pinino' i manglo'.
(When it thunders a lot, and the rain is light, it's good, because it kills the wind.)
It's up to you what you want to hold as true!