How Hurricane Melissa was Impacted by Climate Change: Part 1

A lot of information has been circulating online about whether an extraordinary hurricane like Melissa may have been due to climate change. Before we go into the details, I want to make it abundantly clear: we cannot say definitively that an individual storm was or wasn’t caused by climate change. There is simply no way of knowing whether that individual event would have been present without climate warming. Instead, one thing we can do is look for trends in hurricane-related statistics over longer periods of time to try and determine whether there are relationships between the statistics and climate and the degree to which climate warming is responsible. Another approach is to use numerical models to compare how probabilities in modeled hurricane characteristics differ between scenarios with and without anthropogenically driven (i.e., human-induced) changes to our climate.

We will focus on the first approach to examine historical trends in hurricane-related statistics and their relationship to observed changes in the atmosphere and ocean. This is still a very tricky area, as the historical record for hurricanes has its issues (particularly before the 1970s, when satellite observations were limited and many storms were likely missed) [1]. Nonetheless, in this blog series I will try to summarize the information that scientists do know with confidence regarding Hurricane Melissa and the (albeit) limited historical record of hurricanes in the Atlantic going back to 1970. We will start with Part 1: focusing on Hurricane Melissa’s characteristics more specifically. Part 2 will investigate how Melissa fits into the broader climate system as a whole.

Part 1: Melissa’s Impressive Feats

            It goes without saying that Hurricane Melissa was an incredibly impressive hurricane. Based on preliminary data, the system is tied for being the third strongest hurricane on record in the Atlantic basin [2]. It is possible that the National Hurricane Center may even revise Melissa’s intensity upwards in the post-season analysis once the agency has analyzed the data more completely. I say this because, while the official peak intensity was placed at 185 miles per hour with a central pressure of 892 mbar, there are reports of extremely high winds that were recorded in the eyewall of Melissa just before landfall [2, 3]. The most notable of these came from the US Air Force Hurricane Hunters, where a dropsonde recorded a wind speed of 219 knots (252 miles per hour) [3]. However, this report is currently flagged as “pending verification after the season.” Regardless of whether the measurement was accurate, it suggests that the dynamics inside Melissa’s eyewall just before landfall were extremely violent. Many meteorologists pointed out striking mesovortices in Melissa’s eye when it had reached peak intensity, a testament of the incredibly unstable atmosphere in the eyewall of the storm (Figures 1 and 2) [4, 5, 6].

Figure 1: Hurricane Melissa Visible Satellite Imagery from GOES-19 before landfall in Jamaica. The concentric rings around the storms eye are gravity waves, often seen in incredibly powerful hurricanes. Borrowed from: https://satlib.cira.colostate.edu/event/hurricane-melissa/

Figure 2: Zoomed-in view of Hurricane Melissa near Jamaica. Note the spinning vortices inside the eye of the hurricane. Borrowed from: https://satlib.cira.colostate.edu/event/hurricane-melissa/

Hurricane Melissa’s intensity alone was a striking feature of the storm. But what else is striking is the fact that the hurricane never weakened on approach to Jamaica [7]. Most powerful hurricanes go through what are known as eyewall replacement cycles (ERCs) – where a secondary, larger eyewall begins to form around the main, smaller one, eventually causing the smaller eye to erode and become replaced by the larger one [7, 8]. Yet this never happened with Melissa, which is a big reason why the storm never weakened, since ERCs usually result in temporary weakening as the structure of the eye reorganizes [7, 8]. Why some hurricanes go through ERCs while others don’t is an area of active research [9]. However, a few factors likely contributed to the lack of an ERC in Melissa. For one, Melissa intensified very quickly, jumping 70 mph in wind speed from a tropical storm to a Category 4 in just 24 hours – one of the fastest rates of intensification on record [10]. ERCs require time, and it possible that the storm likely reached its thermodynamic ceiling before that process could begin [11, 12, 13]. Another factor is that the environmental conditions around Melissa stayed nearly perfectly steady. ERCs are often triggered by subtle changes in the environment around a storm, such as shear fluctuations or dry air [11, 12, 13]. Furthermore, analyses suggest a strong inertial stability barrier, meaning the rotation rate increased sharply toward the center, suppressing outer convective bands [14, 15]. Essentially, Melissa’s core was too tightly wound for an outer eyewall to spin up.

In the next blog post, we will discuss how Melissa fits into the context of a warmer climate. Are there any trends in hurricane numbers or intensity with global warming? What do scientists expect for future hurricanes? Stay tuned for Part 2.

References

1.     https://science.nasa.gov/mission/goes/

2.     https://weather.com/storms/hurricane/news/2025-10-28-hurricane-melissa-most-intense-atlantic-hurricanes-landfalls

3.     https://yaleclimateconnections.org/2025/10/catastrophic-hurricane-melissa-hits-jamaica-as-the-strongest-landfalling-atlantic-hurricane-on-record/#:~:text=A%20dropsonde%20released%20by%20the,gust%20ever%20measured%20by%20dropsonde.

4.     https://satlib.cira.colostate.edu/event/hurricane-melissa/

5.     https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/abs/an-experimental-study-on-hurricane-mesovortices/12FA301C994DDFFA3F3845977592609C

6.     https://weather.com/science/weather-explainers/news/2025-10-27-weather-words-mesovortices

7.     https://yaleclimateconnections.org/2025/10/cat-3-hurricane-melissa-hits-cuba-speeds-through-the-bahamas/

8.     https://www.theweatherprediction.com/habyhints2/412/

9.     https://journals.ametsoc.org/view/journals/mwre/140/12/mwr-d-11-00349.1.xml

10.  https://www.climatecentral.org/tropical-cyclones/melissa-2025

11.  https://met.nps.edu/~mtmontgo/papers/secondary_eyewall_formation_2008.pdf

12.  https://keio.elsevierpure.com/en/publications/a-dynamical-mechanism-for-secondary-eyewall-formation-in-tropical/

13.  https://www.jstage.jst.go.jp/article/jmsj/97/1/97_2019-008/_article

14.  https://www.euronews.com/green/2025/10/29/scientists-explain-how-hurricane-melissa-became-a-beast-among-a-string-of-monster-atlantic#:~:text=When%20Melissa%20came%20ashore%2C%20it,records%20for%20the%20strongest%20hurricane

15.  https://www.researchgate.net/publication/246463739_Inertial_Stability_and_Tropical_Cyclone_Development