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Idalia went through 'rapid intensification.' You're likely to see the term more often

MARY LOUISE KELLY, HOST:

Tropical Storm Idalia continues to churn its way across the southeastern U.S., flooding communities and wreaking havoc. The storm made landfall early this morning as a hurricane on Florida's Gulf Coast. That is after it went through what meteorologists call rapid intensification, and that is a term you might want to become familiar with. Nathan Rott of NPR's Climate Desk joins me. Hey, Nate.

NATHAN ROTT, BYLINE: Hey, Mary Louise.

KELLY: So the term rapid intensification - this seems intuitive. This is a storm that gets intense really fast, right?

ROTT: Yeah, it's a rare scientific term that kind of speaks for itself, so let's celebrate that. But there is also a technical definition for this, too, and that's an increase of wind speed of at least 35 mph in under 24 hours. Idalia went from a tropical storm over Cuba on Monday night to briefly a Category 4 hurricane last night. So we essentially saw an increase in wind speeds of about 55 mph in a 24-hour window. So it's textbook rapid intensification.

KELLY: It's textbook. Is it normal - normal to see a hurricane get so much stronger in such a short window?

ROTT: It's becoming normal. I talked to Gabe Vecchi - Gabe Vecchi, I should say - a professor at Princeton University who focuses on hurricanes and climate, earlier today, and he said that the term rapid intensification used to be pretty niche in his community.

GABE VECCHI: Because it was a very unlikely thing. It didn't happen very often. It has unfortunately become a much more common occurrence. I think that for the past few years there's been rapidly intensifying storms in the Atlantic. And so it's something that we should all familiarize ourselves with.

ROTT: And some of those storms he's alluding to there were some of the most destructive we've seen in the U.S. I mean, Hurricane Harvey in Houston, Hurricane Maria which devastated parts of Puerto Rico, Hurricane Ian last year in Florida - you know, it's important to note here, Mary Louise, that even though wind speed is what determines what category a hurricane is, the thing that causes the most damage and deaths during a hurricane is almost always water - either rain or storm surge, like the kind we've seen hit big parts of Florida today. So just because a hurricane is a Category 1 or a 2, it doesn't mean it won't cause a lot of problems.

KELLY: Got it. OK, so I'm still trying to figure out what causes this - what causes rapid intensification.

ROTT: All right. So there's two major ingredients. The first is warm water. You know, think of warm water, hot water as kind of the fuel that powers a hurricane. I was just in the Florida Keys last week doing some other reporting, and I can tell you that the waters in the Gulf of Mexico are very hot. The other ingredient that's needed is wind. Basically, if there's strong upper-level winds, it can prevent a storm from intensifying, so you need less of that wind.

KELLY: And I have to ask - how much of all this is influenced by climate change?

ROTT: So any climate scientist, hurricane expert that you talk to will basically say, we can't immediately say that a hurricane like Idalia is the direct result of human-caused climate change. Hurricanes happen. They happened before we started spewing planet-warming gases into the atmosphere. They're going to continue. What we can definitively say is that the conditions which make rapid intensification more likely - specifically hot water temperatures - now exist more often because of our actions.

KELLY: All right. NPR's Nathan Rott from our Climate Desk reporting there. Thank you, Nate.

ROTT: Yeah. Thank you, Mary Louise. Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.

Nathan Rott is a correspondent on NPR's National Desk, where he focuses on environment issues and the American West.