"Raining Cats and Dogs?"

Today one of my students said, "Tomorrow it will rain cats and dogs". This idiom means that it's raining A LOT!

This is a very interesting idiom and it's in many ESL books. But Americans rarely use it!

What do we say instead?

• It's raining hard
• It's pouring (rain) (out)
  
• It's raining like crazy

So, my student could say:

"Tomorrow it's supposed to rain really hard"

or

"It's going to be pouring tomorrow"