Never seen the centered writing style used like this, it's an interesting thing. I don't know if you plan on keeping it a short story, but if as you go on and continue it, definitely put more detail into the descriptions and the paragraphs. The more detail you can stuff into a paragraph, without making it a run on, the more the reader is invested into your world you've created. And for post apocalyptic writings, that is key. You want to make sure the reader knows how nearly every detail has changed. If someone isn't interested or invested in the setting and how people are reacting to the change in it, then that's something you'd have to improve on.

I liked the dialogue in the middle of sentences, but sometimes you can go a long ways without including any dialogue at all. In the book I am writing I sometimes include dialogue after three or four paragraphs of pure setting, thought, and action descriptions, it creates a placid mood that is always on the verge of shattering into violence and destruction. Keep writing this though. The more your write the more you will improve.

Lots of detail is great, it puts the setting into the right places and gets readers invested in the people and their actions within the setting. Dialogue is good, it reminds people that there are characters. But for post apocalyptic and survival stories, getting that setting down is probably the most important thing. If it is to remain a short story, then the smaller paragraphs are fine, but generally, 5+ sentences are the best.

Hope you found this helpful.

I appreciate all the help I can get, I sometimes worry about making environments too detailed thinking that it denies the characters breathing room and doesn't actually show them or convey well at all. I sometimes wonder if a story gets too "boring" during the beginning and some might prefer action to start as soon as possible. I agree that character development and environment descriptions are important, but I'm just stuck on how to approach it

If you're looking for more of an example of how another writer does, it, I write my own post apocalyptic book, should be in my gallery, the Nocturnal Chronicles. Might help