This photo I found quite interesting. Instead of monotone grays. There is a highlight of blue. Though this image and the image below I tried to focus more on the shapes of storm clouds. Are the dark areas just gather like that or is there any actual pattern involved.
Impending doom. This large scale cloud mass seems to be never ending, like it was slowly creeping above you. To encompass you in never-ending storm clouds. The further you walk into the heart of the storm, the darker it gets.
This reminds me of the fight scene in Lord of The Rings - The Return of The King. The fight of Pelennor Fields. Where the representation of light being swallowed by this large, brooding force of darkness. It's overwhelming, covering everything in it's path in shadow. There doesn't have to be a lot of tonal differences, you already assume it's a storm with the large colour contrast.
Looking further into cloud forms and shapes. This government article lists various types of clouds and what they do. It clued me into a general understand of clouds and how to differentiate them.
