It really looks worthy of something stronger than "raining cats and dogs", although it is as you say and all the impression is not captured in the photos, even in a video the full intensity of a storm may not be reflected.
The phrase caught my attention, because in my tierre I have also heard people using it, in addition to others that are very typical of us, such as saying “it rains a cantaro”, a cantaro is an old large container used to store water, today in disuse day, but in some parts the phrase is still as I remember.