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.
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