Brainstorm Answer: Where Can A Hurricane NOT Form?
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Hi, I'm Dave Thurlow for the Mount Washington Observatory and this is The Weather Notebook. Hurricanes and hurricane formation was the topic of the most recent Brainstorm question. Specifically, I asked where is the only place in the world that a hurricane can not form.

First of all, several people called in to state what seems to be the obvious:

"A hurricane cannot form over land."

But that's not strictly true. It is physically possible for a hurricane to form over land, some very, very wet land, but land. The question probably could have been stated with the qualifier 'aside from land'... but it wasn't.

Many of you shared the opinion of Bill Greenwood, a listener of WVUB in Vincennes, IN: "My guess is the North Pole or the Arctic Circle, around that area."

Again, not impossible but unlikely. But some meteorologists notice some similarities between arctic storms and hurricanes. (that's a show for another day)

So where are there no exceptions, no hurricane formation possible. Cathy Quinn of Grand Marais, MN, who listens to WTIP knows:

"I think the answer to your Brainstorm question is the equator."

That's right, the equator. A hurricane has to spin. And what makes a hurricane spin is something called the Coriolis effect. Precisely at the equator, the Coriolis effect doesn't exist. So, precisely on the equator, even in the ocean, hurricanes can not form.

Thanks to everyone who wrote or called in. And be sure to tune in tomorrow for a new Weather Notebook Brainstorm. Special thanks go to Listener Services Coordinator Susan Ross Parent. Our show is underwritten by Subaru, the beauty of all wheel drive with major support provided by the National Science Foundation.