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...