As hurricanes Florence, Isaac, and Helene take shape across the Atlantic and barrel toward the East Coast of the United States, a huge amount of behind-the-scenes activity is going on around them.
Scientists are looking at them from above and below, and attempting to give the public an inkling of the storms’ impact. It’s a massively complicated task and one that hasn’t advanced as far as you might imagine. In fact, to this day, the best way to know what’s happening inside a hurricane—and glean its future—is to fly a plane right into the swirling gyre.
Predicting hurricanes is very difficult. The reasons why are complicated, but as we learned in the first part of this series, it has a lot to do with the fact that while there is a very specific recipe for making a hurricane, there’s no clear one for what makes a hurricane strengthen or weaken. Those are areas of active scientific research. For example, Rosimar Rios-Berrios, an atmospheric scientist at the National Center for Atmospheric Research (NCAR), is currently studying how the distribution of clouds can make a storm increase in strength. One of her findings (which has also been found by other scientists studying this) is that for a storm to gain strength, the clouds must wrap themselves evenly around the eye, the center of low pressure, before it can intensify. “If they don’t wrap around, you can say that, for the next 12 to 24 hours, it’s not going to become intense,” she says.
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Her colleague at NCAR, meteorologist Stephanie Stevenson, is working to understand the correlation between lightning in a storm and its intensity. According to Rios-Berrios: “It turns out that frequency of lightning and where it is happening geographically can give us an idea if the hurricane will become strong or not.” This research could one day give forecasters some assistance by using the occurrence of lightning to help predict the future intensity of a storm.
All that said, there’s a lot we haven’t learned, according to Allison Wing, a professor of Earth, Ocean and Atmospheric Science at the University of Florida. For example, new research is the first ever to study the global speed of hurricanes. Conducted by James Kossin, a climate scientist at the National Oceanic and Atmospheric Administration’s (NOAA), the research found that in recent years, hurricanes have actually slowed down—which can be dangerous even if they don’t have great intensity. “We don’t know why [they are slowing] at all,” says Wing. “That’s important because if a hurricane is moving slowly it sits over one place and rains a lot for a while. Then it can change the impacts that hurricanes have.”
Because there is great uncertainty surrounding hurricanes, how they work, and why they behave the way they do, it’s a big challenge to predict their course and impact. Currently the best way to accomplish this is by making a computer model of the storm. Much like climate models but on a smaller scale, scientists will input all the data they can gather on a hurricane and the computer will return, say, a thousand different possible options for how the storm will progress. This is what creates that cone-shaped map of potential storm paths you often see in the days before a hurricane makes landfall—it’s a mashup of all the possible outcomes based on what scientists are able to learn about the storm.
So how do they get this data? Well, the first way they get it is through satellites trained at Earth that capture images of the storm. And there are a few buoys here and there in the Atlantic that pick up and transmit data, but in order for those to work the hurricane will have to pass over them directly—not an easy task considering the vastness of the ocean. To this day the most reliable and useful way to gather the largest amount of data about a hurricane is to fly a plane into it.
“I do not think you can ever understand the storm without being inside it,” says Major Nicole Mitchell, a meteorologist and aerial weather reconnaissance officer with the U.S. Air Force. She is one of 20 people in the 53rd Weather Reconnaissance Squadron that makes up the Hurricane Hunters—a group of pilots and scientists who gather data about every storm that could potentially threaten the U.S. “Satellites are getting more fine-tuned, where they can pick up winds, but that’s a picture from above. A thick cloud layer means you can’t see what’s under it.”
To truly understand how a storm is moving and behaving you need to know its centerpoint, she says. “Our number one job is to find the dead center. And a lot of storms don’t have those pretty eyes. [Often] we get an estimate of where we think the center is and then we find it 60 miles off,” she says. “The center of the storm, where that circulation point is, that’s what’s eventually going to hit someone. When they’re projecting the track they want a good initialization point. The whole thing is moving, but what we forecast is based on the center so we want that point to be as exact as possible.”
To pinpoint the center, the Hurricane Hunters measure the direction of the wind as they fly through. “If we point the nose in and the winds are perpendicular off our left wing we’re going towards the center. Then we’ll actually see the winds all of a sudden shift so they’re off our right wing,” she says. That’s an indication that the winds have come full circle and they’ve passed through the eye of the storm.
And because the storm is moving and constantly changing, the Hurricane Hunters will be out flying through a small disturbance that could become a hurricane all the way up to a Category 5 storm. When a cyclone gets big enough they’ll maintain a near-constant presence inside the storm, gathering all sorts of data from wind direction and speed to temperature and pressure. In larger storms they’ll deploy dropsondes (disposable data collection devices that collect data as they fall) throughout the storm, but especially at the center because the pressure measurement there is how storms become officially classified. Everything gathered by the devices and sensors on the plane is automatically transmitted in real time via satellite uplink directly to the Global Forecast Model at NOAA.
“People pay more attention when [a storm] is close to the coast. By that time we’ve been flying it for a while. We’ll even fly a suspect area and a cluster of clouds that has potential. Once it has circulation at a minimum we’re flying it twice a day and once at night. By the time it gets close to a coastline we have planes in and out collecting data almost 24 hours, a lot of times we'll even pass each other in the air,” she says. Each plane will fly the storm for about six hours per shift. “The most you would have a plane not in there would be just under 3 hours.”
As for what it’s like flying through a storm, Mitchell says it’s not always bumpy. “I would actually say the worst bumpy storms aren’t necessarily the worst storms. It’s the ones that are rapidly intensifying. We can see a little more lightning, sometimes hail,” she says. And if part of the storm is over land (the Hurricane Hunters only fly over water) it can get very turbulent. “I flew tropical storm Fay [in 2008] that crisscrossed all over Florida. As it was passing over Hispaniola they have mountains that are over 10,000 feet. Even though we were on the water side the atmosphere is like a fluid, if you make ripples on one side [they oscillate out to the other side]. I remember that flight being really: ‘Oh my gosh!’ Because it was rippling turbulence all over the storm. The military doesn’t make anyone do this job so most of us that do it have strong stomachs.”
But, she says, she doesn’t find it scary. “I have to be entirely honest, this is just me, as a meteorologist who loves science and adventure I’m like “WOOHOO!” I think it’s fascinating. A really classic hurricane is just so fascinating as a scientist.”
One of the most important aspects of much of this science is that it’s very often publicly funded. NOAA, NCAR, and the National Weather Service (which is part of NOAA) depend on favorable budgets from the U.S. government and our tax dollars to do their job. It’s important to note the role that public contributions to science ultimately play in the safety, preparedness, and awareness of Americans. The Hurricane Hunters, for example, are the only pilots in the world that are flying through hurricanes. Though a few other countries have considered it, not one has ever created a program to fly data-gathering planes through these storms. Without them, however, our understanding of a hurricane’s potential impact would be significantly diminished.
Beyond that, science still has much to learn! Every new piece of knowledge that scientists gather about how hurricanes work and why they behave the way they do makes us safer when they eventually make landfall. According to Wing: “We haven’t solved everything yet which is why it’s exciting. We’re finding new things and always improving our understanding. And it’s so important. Meteorology, weather, and climate affects all of us but there’s a lot we don’t understand.”
