How to make ideas as different as types of weather sound like they belong together?

I have had this idea come time and again for me to write a suite about different types of weather. However, when I think of the different types of whether in musical terms, each one is different. Here is what I think of when I think of different types of weather in terms of music:

• Sunny: Glory of the major key, no hint of minor, Majestic sound, Moderate tempo, Graceful melody over nice sounding chords with maybe even a fugato thrown in in the middle of the piece, More likely to be a sharp key, Plagal motion
•     Windy: Lots of melodic motion, even in the bass, Emphasis on scales and arpeggios, Minor or major, depends on the context(just a breeze or a light gust, Major, a strong gust, Minor), Tempo also depends on context
•     Cloudy: Moderately slow tempo, Like Sunny in that it is a melody over chords with maybe a contrapuntal section, but the contrapuntal section doesn't amount to a fugato, just free counterpoint, Minor key
•     Rainy: Slow tempo(like Adagio or slower), Lamenting, melancholic melody in a minor key, Pulse kind of like the human heart to represent raindrops falling, Exchange of bass and melody roles between hands, Never breaks completely free from the minor tonality for the entire movement
•     Thunderstorm: The dramatic climax of everything, Diminished chords used as dominant substitute and to modulate, Loud dynamic overall, with only a few quiet sections, Chord progression in the bass representing the rumbling thunder, Chords in the right hand representing the lightning strike, Minor key(in particular, I always tend to gravitate to C minor for this, probably has to do with my Beethoven influence), Melodic chaos that somehow doesn't sound wrong, Lots of turbulent octaves in the bass, Presto tempo, Calm interlude before the next movement
• Snowy: Major key, More grace notes and staccato to represent the snowfall, Glistening melody to represent the beauty of the snow, More likely to be a flat key

As you can see, with the exception of the Sunny and Cloudy movements, about the only parallel between movements is whether it is major or minor. 6 movements though doesn't seem like enough. That sharp to flat motion(like for example D major to Bb major) just seems inconclusive to finish with. It feels as though I need a concluding seventh movement. Does this have to be some weather phenomenon like say a rainbow to fit in with the theme of the suite being weather? Or does it just have to be like a coda to all the movements?

And, how can I get these disparate movements that work perfectly well as separate pieces to form a cohesive suite when there is so much change from 1 movement to the next. As an example, take the Sunny and Windy movements. The melody goes from being majestic, like the sun, to being fast and uncertain. The bass goes from mainly chords to having an equal melodic role. The key goes from major to minor. The tempo changes. Nothing seems similar about these 2 movements. But if you look at how weather goes from sunny to stormy, the wind precedes the cloudy weather, there might be rain a few days before the storm, and then the storm hits.

So, how can I make all of the movements make sense both as separate pieces and as a suite when they, for the most part aren't similar to each other and they don't share a common tonality? In other words, how can I make my suite cohesive when the individual movements aren't all that similar? It was suggested to me by someone outside this forum to have a prelude at the beginning to start the piece as well as a finale that basically functions as a coda of the entire suite.

I think this is absolutely arbitrary and subjective.

What you propose for "Sunny" doesn't bring the idea of Sun to me.

Yes, it's good to take this ideas to compose suites, etc... But I should take resources from whatever origin. 
Describing things in music is impossible (except perhaps for Wagner ¡?), 
but you can make an interpretation of what Sun is for you and translate into music, 
no matter if it's major or minor. For me, composing in that
way is like being in "a jail of tonalities". 
Meny times the glue of a suite is just the theme, the general style probably.

I recommend you take a look at Saint-saens carnival of the animals, and how he uses orchestration and musicality to portray certain animals, that's one route you can take. 

 you can also make each wether have a certain motif and build on them, and combine them together, either way. 

It's possible that contrast can hold something together.

The same way you can mix different clothing together or 

different colors of paint on a wall.

When you go about writing it, I'm sure you'll come across

some things you'll find tie it together or are common throughout.

If I was going to write the piece, maybe having the idea of sunny be 

something somewhat sad and depressing. And having that 'surprise'

element as a common theme. But who knows you'll have to try it.