FROMLINE: Robert C. Jones Jr.
Newswise – It’s arguably the National Hurricane Center’s (NHC) most iconic graphic: the Tropical Cyclone Track Forecast Cone, which communicates the most likely path of the center, or eye, of a cyclonic storm.
Since its introduction more than 20 years ago, the graphic has been misinterpreted by many people. Some incorrectly assumed that areas outside the cone were safe from the threat of storms.
Now, nearly two years after a University of Miami study found that a redesign of the graphic could help clear up the confusion that surrounds it, the hurricane center will launch an experimental version of the forecast cone to highlight the dangers for people to better face tropical storms and hurricanes making landfall.
While the modified version of the graphic that the NHC will use in both the Atlantic and Eastern Pacific basins starting with the 2024 hurricane season will still feature the familiar forecast cone, color-coded tropical storm and hurricane warnings will now appear alongside it.
The graphic has gone through a handful of iterations since its introduction on July 14, 2002 for Tropical Storm Arthur. The latest version was adopted in 2017 to include the size of the wind field at the time of a recommendation.
“The main criticism of the cone from the start was that it gave people the wrong impression that it suggested a threat – if you’re inside the cone you’re in trouble and if you’re outside the cone you’re in Danger.” I’m fine. But that’s not at all what it’s supposed to indicate, and it’s a dangerous misinterpretation,” said Brian McNoldy, senior research fellow and tropical cyclone expert at the Rosenstiel School of Marine, Atmospheric, and Earth Science.
“In this release, the change reduces the visibility of the track forecast cone when it is over land where wind-related watches and warnings are in place,” McNoldy explained. “The appearance does not change at all when it is over water, which is the majority of the lifespan of most storms. Importantly, this year’s experimental graphic shows hurricane and tropical storm watches and warnings on the map, including inland areas. The cone graphic has always included these watches and warnings, but they were only displayed along shorelines. The inland expansion reflects the reality that a hurricane does not disappear on the coast.”
The debate over the cone reached its peak in late September 2022, when powerful Hurricane Ian reached Florida, eventually making landfall as a Category 4 storm near Cayo Costa in Lee County and subsequently devastating that county’s other barrier islands. Many residents said Ian’s trail surprised them. But in reality, the landing location of Ian’s center ultimately remained within or on the edge of the cone throughout the entire prediction cycle.
“The center line of the route forecast fluctuated, as it often does,” emphasized McNoldy. “But the cone containing the most likely trajectory did its job perfectly and always contained the possible landing point.”
McNoldy is part of a team of researchers that conducted a U-LINK (University of Miami Laboratory for Integrative Knowledge) study that examined why so many people misinterpret the NHC’s cone graphic.
For their study, they surveyed more than 2,800 Florida residents about their understanding of the track cone and found that many of the respondents misinterpreted various aspects of the graphic – for example, some believed they would be safer if they were just outside the track cone while others assumed that there was no risk at all beyond the boundaries of the cone.
“Residents surveyed for our U-LINK study were interested in a graphic that would help them know what to do and when,” the research team said in a statement. “The new experimental graphic developed at the National Hurricane Center takes an excellent step in this direction by highlighting tropical storm and hurricane warnings both on the coast and inland. It provides a more direct way to understand the potential impacts than the old graphic.”
The U-LINK research project is one of several studies over the past 17 years that have found difficulties in interpreting conic graphics. “Although our study may not have had a direct impact on redesigning the NHC cone, it provided supporting evidence that redesign would be useful,” the U-LINK researchers said.
With funding from the National Oceanic and Atmospheric Administration (NOAA) Social Science Program, the team is continuing their research and developing experimental graphics to better communicate potential threats from wind, flooding and storm surge.
“We conducted a series of experiments and participatory design activities with the public and conducted interviews with broadcast meteorologists and emergency managers to test these graphics,” said Barbara Millet, director of the University of Miami User Experience Lab and assistant professor of interactive media in the Department of Communication. “Feedback from these research activities, along with input from our NOAA staff, will be used to refine and improve the experimental graphics.”
The Rosenstiel School’s Sharan Majumdar, professor of atmospheric sciences, and Kenny Broad, professor of environmental science and policy; Scotney Evans, associate professor and chair of the Department of Educational and Psychological Studies in the School of Education and Human Development; and Alberto Cairo, associate professor and Knight Chair of Visual Journalism in the School of Communication’s Department of Journalism and Media Management, also participated in the study.
While the track forecast cone has been called all kinds of names, most notably the “cone of uncertainty,” those names are not the official title, “and therein lies part of the communication and interpretation challenge,” said Jamie Rhome, deputy director of the NHC , back in October 2022. “These unofficial titles could convey a message that is not always consistent with the intended application of the track forecast cone.”
It remains to be seen how effective the hurricane center’s redesigned cone graphic will be once unveiled, McNoldy said. “It’s difficult because the answer depends on what kind of storms will hit us in 2024,” he said. “People respond to weaker storms very differently than to stronger storms, and stronger storms will make greater use of the inland range of watches and warnings.” However, in my opinion, it is a positive change as it clearly shows that the hurricane threat is far from present Center of the storm, extends far inland and especially outside the cone.”