August Dragon

This is a very powerful, evocative picture. Comparing lighting to a dragon is especially true for asian dragons, with their endless coils and winding tails. In my mind's eye this gives the whole piece a very oriental feel.

Now, in the poem's description you mentioned you were not sure about punctuation. I think it's quite alright but I'd like to point out a couple other things.

First and foremost, the length of the poem. You used the 5-7-5 syllables scheme. That's OK, though you should be aware that that is not the most important feature of a haiku, nor is it a defining characteristics according to both Japanese and English contemporary standards. There's an argument to be made that "syllables" is not the correct metric here, as (traditional) haiku have 5-7-5 on ("sounds"), not syllables. An on is not the same as a syllable, and therefore these cannot be used interchangeably. *mcdermid wrote a great article elaborating on this: Counting Syllables.

Now... With the constraint of a set number of syllables out of the way, I would suggest getting rid of all non-essential information. The key to writing good haiku is brevity and minimalism, so:

Thunder rolls –
a heaving dragon crawls
toward sunset

In fact, try this:

Toward sunset
a heaving dragon crawls –
thunder rolls

This inversion accomplishes two things.

First, we preserve the natural, chronological order – we see the "dragon" first, and then hear the thunder, right?

Second, and perhaps more importantly, this (hopefully) creates a moment of surprise, when the reader realizes the dragon is actually a bolt of lightning only after getting to the last line. This sort of word play is also a very typical haiku trait (though not mandatory in all haiku, of course).

I hope you find the above helpful. Do let me know if you have any questions or comments.

Oh, and I realize my revised version is far from perfect. It was just included here to illustrate my point. You are welcome to take it and improve it – it is, after all, your poem.

Once again, thank you for this image! I'm counting on seeing your August dragon in new incarnations soon, in many new poems.