First off, decent harmonic writing, and solid melodic writing but it's hampered by your lack of dynamism.

That piano, that features heavily here, could seriously use some humanisation. As it stands, all your notes are at the same volume, and a great deal of soft-loud here would aid you when you're trying to convey the feelings of urgency and dread of an impending storm.

There's also not much to ground this mix: where's the bass? It's not just the drums that set the feel of a piece, it's your bass as well, and a groove on the bass would have amped up any feelings of dread.

Now, coming back to what you have. That key change took me by surprise, but it fizzled out really quickly. I would like you to come back to this, extending the piece and making it a good bit longer — there are a lot of good ideas here that I feel that, with a good sense of pacing and that dynamism that I mentioned, could make for a strong piece.