Hurricane Melissa caused catastrophic damage in Jamaica, Haiti, Cuba, the Bahamas, and Dominican Republic. It was a high-end Category 5 hurricane, and one of the strongest hurricanes to make landfall in the Atlantic basin. At the time of writing, the death toll stands at 50, and that is almost certain to rise. The extreme intensity of Hurricane Melissa has caused the Category 6 discussing to resurface, so let's revisit it.
First, let's dig into the numbers for Hurricane Melissa. It was the first Category 5 hurricane on record to make landfall in Jamaica. In fact, no Category 4 hurricane has ever made landfall in Jamaica. Hurricane Gilbert (1988) was a Category 3 storm that devastated the island. Hurricane Melissa will likely end up being tied for the strongest hurricane to make landfall in the Atlantic basin. It had sustained winds of 185 mph and a central pressure of 892 mph. As a reminder, lower pressure means a stronger hurricane. The Labor Day Storm of 1935 had a pressure of 892 mb, and Hurricane Dorian (2019), which stalled over the Bahamas, had 185 mph winds.
Gilbert, though a benchmark storm for many, was not in the same class as this storm. To me, Melissa, was a "super hurricane." Why am I calling it that? The strongest tropical cyclones, on average, typically happen in the Pacific Basin and are called typhoons. Encyclopedia Britannica noted, "The term super typhoon is used when a typhoon's sustained surface-wind strength reaches 240 km (150 miles) per hour, the equivalent of a strong category 4 or category 5 hurricane." Hurricane Melissa had winds well in excess of that threshold and on the upper end of Category 5. In fact, it was stronger than any Pacific basin typhoon in 2025.
Colleagues like noted climate scientist Michael Mann have argued that we are in an era of Category 6 hurricanes already. A study entitled, "The growing inadequacy of an open-ended Saffir-Simpson hurricane wind scale in a warming world," was published last year in the Proceedings of the National Academy of Sciences. That paper also added fuel to the Category 6 fire though authors clearly noted their study was intended to raise awareness of the changing nature of tropical cyclone intensity rather than propose a new category.
The scientific literature suggests ongoing climate change will increase high-end tropical cyclones around the world. The 2025 Atlantic hurricane season has produced 13 named storms so far, and three of them reached Category 5. Candidly, I also assume stronger hurricanes will undergo rapid intensification these days, and studies are starting to confirm that assumption. Water temperatures were extremely warm in the Caribbean Sea near Jamaica.
Earlier in the week I shared with my students at the University of Georgia something that amazed me. Hurricane Melissa meandered around for days but did not churn up a lot of cold, deeper water as hurricanes often do. It had ample ocean heat content to become a historically strong storm, and this is reflected above in the sea surface temperatures before landfall. Hurricane expert Brian McNoldy made a similar point recently on social media. He wrote, "Slow-moving Hurricane Melissa managed to cool the extremely-anomalously-warm central Caribbean Sea down to right around average for the date. Instead of a "cold wake", would that be an "average wake"?"
According to NASA, "About 90% of the excess heat from planetary warming over the past century has been absorbed by the ocean, causing ocean temperatures to rise." Meteorologist Jeff Berardelli suggested water temperatures were roughly 4 degrees warmer than they would have been 100 years ago.
Katharine Hayhoe is the Chief Scientist at The Nature Conservancy. She agreed with Mann that Category 6 is a better option for depicting contemporary and future intensity potential. She also told The Independent that the current scale needs to be amended to capture impacts from rainfall. A new scale has been proposed by researchers at the University of South Florida that captures the full suite of impacts associated with hurricanes.
It should be noted that in Mann's proposal, a storm would be classified as Category 6 if sustained winds exceed 192 mph. With that stipulation, Hurricane Melissa would have still been classified as Category 5 rather than Category 6. There are reports of wind speeds or gusts well in excess of 200 mph. Hurricane Hunter and hurricane expert Andy Hazleton flew into Melissa. He wrote in a public Facebook post, "I couldn't believe the 113 m/s (250 mph) wind value that I saw on my screen processing this sonde in Melissa today. It literally went off the scale. Insane storm that has broken or tied a lot of Atlantic records, and unfortunately made a direct hit on Jamaica today." This will need to be officially confirmed but wow.
I am on record as being hesitant to add a Category 6. My reasoning was anchored in a couple of factors. First, my general feeling is that an impact-based approach is needed. As I wrote last year, "Hurricanes bring multiple impacts to the table including wind, storm surge, rainfall, tornadoes and other cascading effects. The Saffir-Simpson Scale is based on wind and does not adequately convey the full range of impacts." Most of the flooding in southeastern Texas from Hurricane Harvey (2017) happened well after the peak category.
Another problem with the scale is that an increase in category is not a linear or incremental increase in damage potential. Mental models used by people may assume Category 5 is just a "little bit worse" than Category 3 or 4. The increase in damage potential as category increases is actually logarithmic. Common earthquake scales are similar.
That means Category 5 Hurricane Melissa was exponentially rather than incrementally worse than Category 3 Gilbert. It had damage potential that was many times greater than what was experienced in 1988. Rheeda Walker is a Professor of Psychology at Wayne State University. She wrote, "If the difference in damage potential between a Category 3 and Category 5 storm isn't 2, why not use a true number representing what it is?" She went on to say, "In already, complex circumstances, we are asking people to understand logarithms. I believe in meeting people where they are."
The last factor is related to risk communication and sense of urgency. I have always felt that from a risk communication standpoint, Category 5 is adequate. As I wrote in 2024, "From my perspective, a new Category 6 does not add much to the table. To me, it is like changing the sign by the fireplace from "Caution, very hot" to "Caution, very, very hot." However, just maybe this is to oversimplistic.
Residents of the islands are resilient and have experience with storms. In some cases, there are limited economic means to evacuate. However, tourists have more options. It has been reported that nearly 25000 tourists rode out the storm in Jamaica even as messaging, almost a week in advance, sounded alarms that a major hurricane would impact the island. Would Category 6 language have prompted people to cancel weddings, golf trips, and reunions leave? Forecasts, from an intensity and track perspective, provided consistent guidance to make decisions beyond hope or "let's wait and see." Did motivated reasoning or optimism bias rule the day? I am sure a lot of planning and money went into those trips to Jamaica.
I close with a general feeling that a fundamental new approach for messaging hurricane risk is needed, while acknowledging that the Category 6 discussion is anchored in an important narrative about very real changes in extreme weather events. Of course, climate changes naturally. Of course, there were hurricanes before human activities. Neither of those things refutes the fact that hurricanes can be modified by natural variability and anthropogenic activity. Trees fall naturally in the forest, and chainsaws are not a hoax.