When a translator saw "南海夏季风爆发前2 候," she decided to "expand" time :)

So, "2 候" became "two weeks."

No one knows everything, but God (because "God knows.").

But, we all have a mouth, which is for eat, drink, spit, and question. So, next time when you don't know how to translate some words into English, please talk to the author(s) directly.