Platzregen in English:

There's going to be a downpour.

What a downpour!

yesterday there was a big downpour in Suwaki.

We got soaked in a sudden downpour.

Take an umbrella becouse it's downpour.

It wasn't just ordinary rain, it was a downpour.

torrential downpour

Judging from the present look of the sky, we may have a downpour any moment.