Weather forecasting terms explained

There is something to be said about using terms that have the most precise meaning possible.  However, in scientific circles, you may have a better understanding of the nuance in different terms than the colloquial understanding.  Weather forecasting is definitely one of those areas.  The one that I have been wanting to understand recently is showers vs. rain (because you also hear 'scattered showers' which seemed redundant to me if showers are just scattered rain in the first place):

Meteorologist Forecasting Terms: Differences Explained Between Scattered Showers and Rain at Times

• Rain - forms from stratus clouds, more widespread, steady, less intense
• Showers - forms from cumulus clouds, more isolated, short-lived, affects a smaller area, sometimes more intense

So, scattered showers does seem to be a bit redundant if they are already "isolated" and "affect a smaller area".