National Weather Service United States Department of Commerce

October 17, 2022


Q: Post-Hurricane Ian, a lot of people are talking about the hurricane cone issued by the National Hurricane Center. First, what is its official name?
A: Officially, it’s called the Tropical Cyclone Track Forecast Cone. Colloquially, it has been given all sorts of names such as “Cone of Uncertainty” and “Cone of Concern,” but these are not the official name and therein lies part of the communication and interpretation challenge. These unofficial titles might convey a message which doesn’t always align with the intended application of the Track Forecast Cone.


Q: What is the Tropical Cyclone Track Forecast Cone meant to convey?
A: The Track Forecast Cone simply communicates the most likely track of the center — or eye — of a tropical cyclone. The center of a tropical cyclone historically moves out of the cone about a third of the time.* The landfall location of Hurricane Ian’s center ultimately stayed within or on the edge of the cone throughout the forecast cycle. Ian was a particularly large system with impacts that extended well beyond the center, and hence well outside the cone. The way Ian approached Florida at an acute angle meant that relatively small changes in the track direction meant larger-than-normal changes in the landfall location.

The Tropical Cyclone Track Forecast Cone for Hurricane Ian
shows the most likely track of the center of the storm
as it makes landfall in Cuba, Florida and South Carolina.



Photo of Jamie Rhome
NHC Acting Director, Jamie Rhome, warns communities in Hurricane Ian’s path of the life-threatening impacts: wind, storm surge, flooding, and tornadoes during one of numerous social media livestreams

* The cone is formed by connecting a set of circles at each forecast time. Each circle is drawn so that it encloses 67% of the official track forecast errors over the last 5 years.


Q: Immediately after Hurricane Ian made landfall, the cone came under scrutiny, with many claiming that it might have confused people. You stayed out of the conversation until now. What drove that decision?
A: It was premature, given the extreme suffering taking place in southwest Florida and the fact that our partners within emergency management were actively involved in search and rescue efforts. My goal is to help the conversation take place at the right time, in the right venue and in a productive way.

In the immediate aftermath of Hurricane Ian, National Hurricane Center (NHC) staff remained focused on supporting emergency operations associated with Ian — contributing to the search, rescue and recovery effort — and forecasting other weather systems across the tropics. We are still in the midst of hurricane season. We will conduct a careful analysis of the entire forecast and warning process in the coming weeks and months, as we do with every storm.


Q: Do you think the cone confuses people?
A: I think it’s clear that not everyone is aware of our message to focus on hazards, which usually extend well outside of the cone. The National Weather Service (NWS) is working closely with the social science community and NOAA researchers to address this. Prior to Hurricane Ian, efforts were underway to study the cone and other aspects of hurricane risk communication — because this issue is much more complex than just the cone. NOAA-funded researchers conducted risk communication surveys for Ian (as they did for Marco and Laura in 2020, and Henri in 2021). We’re looking forward to their collective findings on public perception and understanding of risk as these storms evolved.


Q: Are you open to making changes to the cone, and if so, how?
A: Absolutely, we’re open to evolving any aspect of our risk communication to be more effective. Every change we make to our operations and communications is grounded in well-researched and methodical social and physical sciences. NHC staff work tirelessly during the off-season every year to analyze the latest research, best practices from the prior hurricane season and input from partners in an attempt to unearth how to best serve public needs.

It’s tempting to want to engineer a quick fix to the cone, but we need to be scientifically disciplined and wait for the body of evidence to come forward, and then determine how to best apply it. We aren’t planning an immediate pivot away from the cone, and I don’t think the cone is ever going to go completely away. It still has merit for conveying high-level information about where the center of the tropical cyclone is likely to move, especially for storms where the entire track is over water.


Q: You were imploring people to focus on the impacts of Hurricane Ian, and not just the cone, since people outside the cone can experience a hurricane’s impacts. What work went into the cone and your communications strategy leading up to Ian?
A: We’ve spent the past 5-10 years working with social scientists to upgrade our risk communications aimed at not focusing on the cone. For example, in 2017 NWS introduced a new warning system to explicitly convey the risk of life-threatening storm surge, including dissemination directly to people via wireless emergency alerts on cell phones. NHC also introduced high-resolution storm surge flooding inundation maps in 2016 and began an experimental peak storm surge flooding graphic in 2021.

All the recent additions to our forecast suite, including new storm surge warnings and maps, were driven by social science to help us communicate hazards — something the cone was never intended to do. The challenge is that not everyone has the time, bandwidth or desire to sift through all this information. The cone is simple and familiar to them, so they make assumptions, oftentimes subconsciously, about what it means.




Q: What are the benefits of the cone? Why do we even use it?
A: The cone provides a geographical reference of where a storm is located and where the center of the storm is likely to go. It is a key hurricane forecast and communication product, but it tells only one part of the story. For a comprehensive picture of a storm’s hazards and impacts, people need to focus on the additional risk communication products NWS issues that convey the hazards, such as the new storm surge warnings and peak storm surge flooding graphic, the excessive rainfall outlooks issued by the Weather Prediction Center, and the probabilistic wind and timing products. These products are amplified by the private sector and broadcast meteorologists to their unique audiences.


Q: Why not include all hazards on the cone?
A: The main hazards of a hurricane are wind, storm surge, rain-induced flooding, and tornadoes. Hazards also include high surf and rip currents, which could extend a far distance from a storm. If we included all of these hazards, the graphic would be too cluttered and incomprehensible to be useful. We do put the current size of the tropical cyclone wind field and any coastal wind-based watches and warnings on the cone to emphasize that wind hazards extend well outside the cone. As discussed above, we produce risk communications for each hazard, which we update every six hours along with the cone graphic.


Q: Any advice for people who found themselves confused by the cone for future storms?
A: The main thing for people to understand is that the cone is a tool that provides a basic geographic reference for the center track of the storm, especially when it’s over water. Actual impacts on land after landfall can extend hundreds of miles outside the cone in all directions. I urge people to pay attention to the hazard-focused risk communications products we package with the cone and distribute every 6 hours.

Four other key points come to mind:

  • The first way to improve individual resilience is to prepare for every hurricane season in advance. Preparedness and knowledge ahead of time will give people confidence and reduce confusion in the moment. And people in general will have a better sense of control and well-being if they plan ahead.

  • The second way is to know whether you are in an evacuation zone and which zone you are in. Know in advance where you will go if you are told to evacuate. Then follow the orders by local authorities. This simple, actionable information can save lives.

  • Third, follow official forecasts as they are updated prior to a storm’s landfall. The cone dynamically changes with each forecast update, so it’s important to stay up-to-date with the latest information and not get stuck on earlier forecast tracks.

  • Last but not least, make risk-averse decisions for yourself and your family based on worst-case, not best-case, scenarios and outcomes, with the singular goal of surviving the wrath of a major hurricane’s impacts – wind, rain, storm surge, and tornadoes. We see a lot of people deciding not to evacuate for a multitude of reasons. But the singular goal of safety needs to drive all personal decisions.