Hurricane Melissa Is Now A Category 5 Storm: What Are Hurricane Categories & What Do They Mean?

Last Updated:October 27, 2025, 15:29 IST

As Jamaica braces for the impact of Hurricane Melissa, here’s a detailed look at how hurricanes form, what sets them apart from cyclones and typhoons, and what each category means

John Tamasa uses a fishing net ahead of Hurricane Melissa, in Portmore, Jamaica, October 26, 2025. REUTERS/Octavio Jones

The Caribbean is now on high alert as Hurricane Melissa strengthens into a rare Category 5 storm with sustained winds of 160 mph (257 km/h). Melissa began as a cluster of thunderstorms off the coast of West Africa before developing over warm waters into a powerful tropical system. It reached tropical-storm status north of Venezuela on 21 October and rapidly intensified over the weekend, evolving into one of the most dangerous hurricanes ever recorded in the region.

The US National Hurricane Center (NHC) has warned of “extensive infrastructure damage, long-duration power and communication outages, and isolation of communities" across Jamaica and nearby islands, with the potential for life-threatening flash flooding, storm surges, and landslides.

But what exactly turns a tropical storm into a hurricane, and how do meteorologists measure its strength?

What Makes A Storm A Hurricane?

A hurricane begins as a tropical disturbance over warm ocean waters. The National Oceanic and Atmospheric Administration (NOAA) explains that such storms often start as tropical waves — clusters of thunderstorms that move westward across the tropics. As warm, moist air rises from the ocean surface, it creates a low-pressure area underneath. Cooler air then rushes in, rises, and forms clouds and thunderstorms.

When wind speeds reach 39 to 73 mph (63 to 120 km/h), the system is classified as a tropical storm. If it strengthens further and sustained winds exceed 74 mph (120 km/h), it becomes a hurricane. Anything below 39 mph (63 km/h) remains a tropical depression.

These storms act like giant heat engines, feeding on warm ocean water, generally above 26.5°C (80°F). As humid air condenses into clouds, it releases heat, adding energy to the system. The result is a self-sustaining spiral that can grow hundreds of kilometres wide.

At the centre lies the eye, deceptively calm, clear, and about 30 to 60 kilometres across. Surrounding it is the eyewall, a violent ring where winds and rain reach their peak. That’s the zone capable of tearing apart homes, uprooting trees, and flattening power lines.

Hurricanes, Cyclones, And Typhoons: What’s The Difference?

They are, in essence, the same phenomenon, rotating systems of thunderstorms and clouds that form over tropical waters. The difference lies in where they occur.

As per NOAA and the Bureau of Meteorology (BOM):

• Hurricanes form over the North Atlantic Ocean and Northeast or Central Pacific Ocean.
• Cyclones develop over the South Pacific and Indian Ocean.
• Typhoons form over the Northwest Pacific Ocean.

These storms spin anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, a result of the Coriolis effect.

The Saffir–Simpson Hurricane Wind Scale

The Saffir–Simpson Hurricane Wind Scale is the standard used by the National Hurricane Center to rank hurricanes by maximum sustained wind speed. It ranges from Category 1 to Category 5, and provides a quick measure of the storm’s destructive potential.

The scale does not factor in rainfall, flooding, storm surges, or tornadoes, which can all cause devastating damage even from lower-category storms.

Category 1: Dangerous But Manageable

Winds: 74–95 mph (119–153 km/h)

These storms bring “very dangerous winds" that can damage roofs, siding, and power lines. Large tree branches may snap and shallow-rooted trees could topple. Power outages can last a few days.

Example: Hurricane Sandy (2012) made landfall in New Jersey as a Category 1 storm, flooding parts of New York City.

Category 2: Extensive Damage

Winds: 96–110 mph (154–177 km/h)

These “extremely dangerous winds" can rip off roofs and uproot trees. Power may be lost for several days to weeks.

Example: Hurricane Floyd (1999) struck North Carolina as a Category 2, causing widespread flooding along the US East Coast.

Category 3: Major Hurricane

Winds: 111–129 mph (178–208 km/h)

A Category 3 hurricane marks the threshold of a “major hurricane", capable of “significant loss of life and damage," according to the National Hurricane Center. Well-built homes may lose parts of their roofs and walls, and utilities can be down for weeks.

Examples: Hurricane Zeta (2020) briefly reached Category 3 before hitting Louisiana, while Hurricane Wilma (2005), one of the strongest on record, made landfall in Florida as a Category 3.

Category 4: Catastrophic Power

Winds: 130–156 mph (209–251 km/h)

As per the NHC, well-built framed homes can sustain severe damage with loss of most of the roof structure and some exterior walls. Trees and power poles are likely to fall, isolating residential areas.

Examples: Hurricane Harvey (2017) and Hurricane Ida (2021) both hit the US Gulf Coast as Category 4 storms, leaving catastrophic flooding and prolonged power outages.

Category 5: The Most Extreme

Winds: 157 mph (252 km/h) or higher

At this level, “a high percentage of framed homes will be destroyed, with total roof failure and wall collapse," says the NHC. Power and water could be unavailable for weeks or even months.

Examples: Hurricane Andrew (1992) devastated Florida, Hurricane Irma (2017) tore through the Caribbean, and Hurricane Camille (1969) brought record storm surges to Mississippi.

A Category 5 hurricane can render entire regions uninhabitable for weeks or months.

How Do Hurricanes Cause Destruction?

A hurricane’s power isn’t just in its wind, it’s in everything that follows. When a storm of that size hits land, it carries the ocean with it. Strong winds push seawater toward the coast, creating a storm surge that can climb up to six metres high and travel several kilometres inland. Entire neighbourhoods can vanish under water within minutes.

Most hurricane deaths aren’t caused by collapsing buildings or flying debris, but by flooding. Storm surges and inland flooding are responsible for most hurricane-related deaths, about three-quarters, according to a study cited by National Geographic.

Flooding is often followed by landslides, especially in hilly or deforested regions, and tornadoes that spin off from the outer bands of the storm, multiplying the chaos. Roads disappear, power lines collapse, and communication networks fail, cutting off communities for days.

The 2005 Hurricane Katrina remains the starkest example of this chain reaction. Making landfall as a Category 3 storm, it killed around 1,200 people, a third of them from drowning, and caused over $125 billion in damage.

Is There A Category 6?

There is currently no official Category 6 on the Saffir–Simpson scale. However, CBS notes that some climate scientists have debated expanding the scale due to increasingly powerful storms, especially as wind speeds in certain hurricanes now far exceed the traditional upper limit of Category 5.

The Global Pattern Of Storms

Hurricane seasons vary around the world. The Atlantic hurricane season runs from June 1 to November 30, peaking between mid-August and late October. The northern Indian Ocean sees most cyclones between April and December, particularly in May and November.

According to National Geographic, the most powerful tropical cyclones often form in the Pacific Ocean, where storms have more room to intensify. Hurricane Patricia (2015) holds the record for the strongest winds ever recorded — 215 mph (346 km/h) — while Hurricane Wilma (2005) remains the most intense in the Atlantic at 183 mph (294 km/h).

Karishma Jain

Karishma Jain, Chief Sub Editor at News18.com, writes and edits opinion pieces on a variety of subjects, including Indian politics and policy, culture and the arts, technology and social change. Follow her @kar...Read More

Karishma Jain, Chief Sub Editor at News18.com, writes and edits opinion pieces on a variety of subjects, including Indian politics and policy, culture and the arts, technology and social change. Follow her @kar...

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