Complex sentence: As atmospheric conditions continued destabilizing across the Michiana region with the afternoon heating; towering thunderheads began to quickly build, pushing higher into the sky; it was only a question of time before the bubble would burst.
Split into simpler sentences: As atmospheric conditions continued destabilizing across the Michiana region with the afternoon heating; thus, towering thunderheads began to quickly build, pushing higher into the sky. It was only a question of time before the bubble would burst.