Eighteen years ago, April and Sean Saunders watched helplessly as their parents were consumed in the wrath of a massive twister. Now April (Mimi Rogers) is a storm chaser seeking to understand every aspect of the forces that ripped her life apart, while Sean moved to Seattle where there is minimal chance of a twister touching down. As April is researching current shifts in weather patterns, she discovers that the path of Tornado Alley may be moving north...with Seattle as the new tornado hotspot. Immediately, she drags her boyfriend and rebellious teenage daughter to Seattle to warn Sean, a city Sheriff. Sean finds April's theory ridiculous; and more importantly, he despises what his sister does for a living?basically chasing the ghosts of their parents. It isn't long before odd weather phenomena begins to wreak havoc on the unassuming city, and April now realizes her prediction is horribly accurate. With a massive storm system brewing, and a category defying twister looming, April must fight against an entire city unwilling to believe, as well as two decades of her own nightmares and demons, in a desperate attempt not to let this deadliest of storms finally get the best of her and her brother.