How do I interpret weather forecasting data for landscape photography?

In order to have better planning for my landscape photography, I'd like to better understand weather forecasting data.

I already know some things like:

1. A cloud coverage between 30 and 70% is the ideal


2. High clouds are what makes the sky red

In many photography blogs, I read that people use satellite and radar data in order to get even more information, but I don't know how to interpret them. I know is they should help understanding how clouds are moving in the sky, so basically understanding if the sun is going to be covered or not, but still I can't manage it.

Answer

If you mean weather forecasts like this one it can only provide general and not-so-reliable information. It is too vague. 30% cloud coverage means that 30 % of the sky is covered by clouds. What type of clouds (cirrus, cumulus, stratocumuls,...) no one knows.

On the other hand, there are detailed models like CHMI's Aladin with different maps. Here the B&W map shows overall cloud coverage (black is bright sky, white opaque clouds), yellow/green/purple maps shows the cloud coverage in different altitudes (again black is no clouds, bright colour is fully opaque clouds). There is also an (unofficial) Android app that processes the data called Aladin.

You can also use actual data from meteoradars (again CHMI's meteo data) in your area and guess how the weather would develop "to the future"... Again, there is an android app for that.

You can look at Windity to see whatever map you want for weather forecast... How accurate it actually is is disputable, but the 5 minute forecast can be reliable.