AUDIE CORNISH, HOST:
When Hurricane Michael in the Florida Panhandle last year, it walloped the coast. Today scientists at the National Hurricane Center said the storm was even stronger than first thought. In fact, it was a rare top-of-the-scale Category 5 hurricane. NPR's Russell Lewis is here in the studio to discuss why the storm's strength was upgraded and how today's announcement changes how forecasters are planning for the coming hurricane season. Welcome back to the studio, Russell.
RUSSELL LEWIS, BYLINE: It's good to be here.
CORNISH: So how did forecasters go back after the fact and decide that Hurricane Michael was indeed stronger when it hit than they first thought?
LEWIS: Well, we knew that this storm was going to be massive, it was going to be strong and that it was going to do a lot of damage. And that's what it did. It ended up causing some $25 billion in damage. It was directly responsible for the deaths of 16 people. I mean, it was a big storm that targeted Panama City and Mexico Beach in the Florida Panhandle.
But Audie, in every tropical system, forecasters - they go back. They analyze lots of things about the storm - its path, how big it was and, importantly, how strong the storm was. At the height of this storm, there were a lot of variables that sort of played into understanding the strength, from offshore winds sensors to the Hurricane Hunter aircraft that are flying in the storm to Doppler radar to satellite analysis.
And given all of that, forecasters now say that Michael reached sustained winds of 160 miles per hour. And we should say that as a Category 5 storm, Michael is in rare company. It joins Andrew, which hit South Florida in 1992; Camille, which struck Mississippi in 1969 and that unnamed Labor Day hurricane of 1935.
CORNISH: But looking back, why did that rapid increase of strength catch people off guard?
LEWIS: You know, certainly with this storm, it went from a Category 2 to a Category 4 in just 24 hours. And as we've learned now, it wasn't a Category 4. It was a Category 5. And it really is a very rare occurrence. But what you normally see is that a hurricane weakens as it gets closer to land but not with Michael. It kept getting stronger until it hit land. And people in Florida probably remember Hurricane Charley doing exactly that same thing in 2004 before it veered and unexpectedly hit southwest Florida.
CORNISH: What are some of the lessons here for the upcoming hurricane season?
LEWIS: Well, I think really Hurricane Michael has become a case study for meteorologists. In fact, the National Hurricane Center is holding its annual hurricane meeting next week in New Orleans, and they're going to be talking about Michael on a couple of these panels.
And really I think this is a good reminder for everyone. A hurricane, regardless of its strength, is very dangerous. We often hear from people who plan to ride out the storms because they think, oh, it's just a Category 1 hurricane, but that is still a hurricane. And as we've seen, these storms can and do become stronger than forecasters predict. And really the wrong time to think about evacuating is when the storm is right off the coast.
CORNISH: That's NPR's Russell Lewis. Russell, thanks for your reporting.
LEWIS: You're welcome. Transcript provided by NPR, Copyright NPR.