It's not your imagination. Hurricanes are getting more severe.

0:00Alejandra Borunda:In late August 2005, National Weather Service meteorologist Robert Ricks in Slidell, Louisiana, was monitoring the progress of a hurricane as it approached the Louisiana coast. You know, we saw another storm thinking, you know, here we go again. But it was going to be more of the ordinary routine drill that we've been through several times before. Ricks expected Hurricane Katrina to be big, perhaps a Category 3 or 4 at landfall. But when that eye exposed itself as large as it was on the satellite imagery and knew that it was a five, then it took on a whole new perspective. At 10 a.m. on the morning of August 28th, Ricks issued an urgent weather message more dire than any he had ever issued before, describing a, quote, most powerful hurricane with unprecedented strength.

0:49I am this morning declaring that we will be doing a mandatory evacuation. And I'm going to read that following news that there's possibly a breach on the levee at Lake Pontchartrain that's pouring more water still into a city that's already flooded. With a bunch of New Orleans now underwater, authorities are focused on search and rescue before it's too late.

1:12Alejandra Borunda:Hurricane Katrina would leave more than 1 ,300 people dead, an estimated 80 percent of New Orleans underwater, and would become the most expensive hurricane in history, with overall economic losses estimated at$125 billion. Katrina was a harbinger of what would happen to hurricanes over the next two decades. Climate change would make them an increasingly powerful and regular threat. Now, millions of Americans from New England to Virginia are bracing for a potential superstorm. Hurricane Sandy is serious. It has already killed 21 people. Hurricane Harvey picks up strength. The storm is now a category three with more than 110 mile per hour winds.

1:57It could bring three feet. A treacherous night ahead for Florida as darkness begins to fall and Hurricane Ian continues its catastrophic rampage.

2:06Alejandra Borunda:Consider this. Hurricane Katrina spurred a better understanding of these intensifying storms. Its devastation led to improved storm preparedness. But two decades after the levees broke, can we hang on to that progress?

2:25Alejandra Borunda:From NPR, I'm Elsa Chang.

2:36Alejandra Borunda:It's Consider This from NPR. The force with which Hurricane Katrina slammed into New Orleans stunned the country. Since then, scientists have gotten much better at forecasting hurricanes and understanding how climate change influences them. But those scientists now fear that progress is in danger. NPR's Alejandra Barunda is here to explain. Hi, Elsa. Okay, so just big picture here. How has hurricane science evolved since Katrina? I'll let Gabe Becky tell you. He's a climate and hurricane scientist at Princeton. It's been a great 20 years. It's been a pivotal 20 years. That's because right after Katrina, scientists from agencies like NOAA and universities and national labs all got together to work on something called the Hurricane Forecasting Improvement Project, or HFIP.

3:25And the project aimed to flash forecast error for both hurricane track, which is where a storm is going, and intensity by about 50 % within 10 years. and it absolutely crushed those goals.

3:37Alejandra Borunda:Crushed? How did they crush those goals? Yeah, so they did two big things. First, scientists needed to build better computer models of the storms. And then they also needed better real observations of the storms. Because the best model in the world isn't super useful if you don't feed it good starting information. And HVIP and other federal efforts helped with both. HVIP was mostly on the modeling side, and other agencies helped improve the observations. Like, NOAA and the Department of Defense launched these special satellites in the 2010s, and hurricane scientist Jeff Masters explains them. These use microwaves, the same things, you know, you use to run your microwave oven on.

4:16And they are able to do kind of a 3D MRI-like picture of the inside of a hurricane. And that microwave data helps a lot. And so does information from the hurricane hunter planes that fly through the storms, getting Doppler radar images, and also drop sensors down through the storm to the ocean surface.

4:35Alejandra Borunda:Wow. Okay, so all of this has added a ton of new useful information, I imagine. Yeah, and it all adds up to big forecasting gains. By last year, a five-day-out forecast of both track and intensity was about equivalent to a two-day forecast in 2005. Oh my god, that's a big jump. Okay, well, what about climate change? Because I'm sure that has had an impact on hurricanes, right? Absolutely. And not only now do we have 20 more years of observations to understand it, but the theory is also way farther along. Here's Becky again. So it's unambiguous that over the last 40 years, say since the 1980s, hurricanes in the Atlantic have become more frequent, more intense, wetter.

5:17Overall, scientists say climate change kind of puts storms on steroids. And a hotter planet, and especially a hotter ocean, means storms can penetrate farther north, too. And they're filled with a lot more water, which actually is what does most of the damage. Last year, for example, Hurricane Helene dropped an extra 10 % more water than it would have otherwise.

5:39Alejandra Borunda:Jeez. So can we expect hurricane forecasts to get even better in the future? So the Trump administration has slashed funding for many of the organizations critical to hurricane science. And so there's now some concern about even keeping up with the progress that already has been made. Kim Wood puts it this way. There are hurricane scientists at the University of Arizona. We didn't get this far by saying, yep, we figured out hurricanes. We're done. We have to continue investing in the observations, in the analysis of those observations. Because that progress has real value. A study from the National Bureau of Economic Research last year found that improvements of forecasts saved the country$2 billion per hurricane because people could better prepare for them.

6:26That's more than the budget of the whole weather service.

6:29Alejandra Borunda:Wow. That is NPR's Alejandra Barunda. Thank you so much, Alejandra. Yeah, glad to talk. This episode was produced by Michael Levitt with audio engineering by Kweisi Lee. It was edited by Courtney Dorning, Patrick Jaron Watanonan, and Sadie Babbitt. Our executive producer is Sammy Yenigan.

6:50Alejandra Borunda:It's Consider This from NPR. I'm Elsa Chang.