Hurricane Melissa and the Case for a 'Category 6' — Are Stronger Storms the New Normal?

Hurricane Melissa underscores a changing hurricane era

As officials continue to assess the devastation left by Hurricane Melissa, a troubling pattern emerges: warming seas are feeding storms more energy, allowing them to intensify faster and reach greater peak strength.

Human toll and damage: The latest tallies report at least 75 deaths and insured losses exceeding $4 billion, with local authorities in the Caribbean estimating tens of billions more in total damage.

Historic intensity: Melissa made landfall in Jamaica with sustained winds of 185 mph, a landfall speed matched by only a handful of Atlantic hurricanes in recorded history — tying Dorian (2019), Wilma (2005), Gilbert (1988) and the 1935 Labor Day hurricane. Only Hurricane Allen (1980) recorded slightly higher peak winds, placing Melissa among the most powerful Atlantic storms on record.

Why oceans matter

The connection between ocean heat and hurricane intensity is well established. Burning coal, oil and natural gas emits greenhouse gases such as carbon dioxide (CO₂) and methane (CH₄), which trap heat that would otherwise escape to space. More than 90% of that excess heat has been absorbed by the oceans, driving up sea surface temperatures — especially in the tropical Atlantic and Caribbean, where hurricanes form.

During Melissa’s rapid intensification, Climate Central reported regional sea surface temperatures about 1.4 °C (2.5 °F) above average. NASA and NOAA data show global ocean surface temperatures have risen roughly 1.3 °C (2.3 °F) since the late 19th century, and the deep ocean is warming as well.

The debate over adding a "Category 6"

Researchers including James P. Kossin and Michael F. Wehner have proposed adding a new "Category 6" to the Saffir–Simpson Hurricane Wind Scale, which currently tops out at Category 5. Their argument: the atmosphere and oceans now allow storms to reach intensities that the original scale did not anticipate, and an open-ended Category 5 may understate the danger of the most extreme storms.

So far the proposal remains academic: forecasting agencies have not adopted a Category 6 nor incorporated it into official warnings.

Any formal change would require institutional decisions, careful public communication, and a reassessment of how categories are used to convey risk in warnings and emergency planning.

What this means going forward

Whether or not a new numerical category is adopted, Melissa highlights two urgent needs: clearer risk communication for extreme storms and stronger action to reduce the greenhouse gas emissions that are warming our oceans. As scientists debate new ways to describe and warn about catastrophic storms, policymakers and communities must prepare for a future in which such events are more likely.

About the author: Thais Lopez Vogel is cofounder and trustee of the VoLo Foundation, which supports science-based climate solutions, education, and health. This opinion piece was distributed by The Invading Sea (www.theinvadingsea.com), a site covering climate and environmental issues affecting Florida and beyond.