SEATTLE - We mentioned yesterday that hurricanes spin counter-clockwise in the Northern Hemisphere, and clockwise in the Southern Hemisphere due to the Earth's rotation and Coriolis Force.
But can a hurricane change sides? It's never been documented. The Coriolis Force is weakest near the equator, so you don't get the turning needed to spin the air into tight low-pressure centers, so they don't form within 5 or so degrees latitude of the equator.
As for a roaring already-formed hurricane to say, march south across the line, it can theoretically happen -- the weak Coriolis Force there would just let it keep its momentum, and if it crossed, the opposite force would eventually tear it apart. But a secondary part of the Coriolis Force tends to pull systems away from the equator, so they'd be pulled back before they reached the equator.
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