Hurricane season is here, and every year, these powerful storms make headlines as they tear through coastal areas, leaving destruction in their wake. But before hurricanes reach land, they begin as simple disturbances over warm ocean waters.
So, how exactly do hurricanes form? Let’s break down the science behind these natural phenomena.
How Hurricanes Form
The Right Ingredients For a Hurricane
Hurricanes, also known as tropical cyclones or typhoons in other parts of the world, are born under very specific conditions:
- Warm ocean water (at least 80°F/27°C) - This is the fuel that powers hurricanes. Warm water evaporates, rising into the atmosphere and creating energy in the form of heat.
- Moist air - As water vapor rises, it cools and condenses into clouds, releasing more heat and building the storm.
- Low wind shear - Wind shear refers to the change in wind speed or direction with height. Too much wind shear can tear a developing storm apart before it strengthens.
- Pre-existing weather disturbance - Most hurricanes start as tropical waves (low-pressure areas moving through the tropics).
The Birth of a Storm
When a tropical disturbance moves over warm ocean water, the heat and moisture rise and spiral due to the Earth’s rotation (thanks to the Coriolis effect). This rotating system starts organizing into a more defined storm system.
But how do hurricanes form in this environment? If conditions remain favorable, the system strengthens into:
- Tropical Depression - Wind speeds less than 39 mph (63 km/h).
- Tropical Storm - Wind speeds between 39–73 mph (63–118 km/h), and the storm is given a name.
- Hurricane: Wind speeds exceed 74 mph (119 km/h).
The Eye of the Storm
The eye of a storm is a calm, clear center surrounded by the eyewall, which contains the most intense winds and rainfall. The spiral rainbands extending from the center can stretch for hundreds of miles.
Why Hurricanes Intensify
The more time a storm spends over warm water with low wind shear, the stronger it can become. Some hurricanes undergo rapid intensification, increasing wind speeds dramatically in a short period of time.
Landfall and Dissipation
Hurricanes weaken when they move over land or cooler waters. Without their warm water fuel source, the storm loses energy. However, by the time they reach land, hurricanes can cause massive flooding, storm surges, wind damage, and long-term disruption.
2025 Hurricane Season Predictions From the National Oceanic and Atmospheric Administration
The 2025 Atlantic hurricane season officially began on June 1 and is forecasted to be more active than usual. The National Oceanic and Atmospheric Administration (NOAA) predicts:
- A 60% chance of an above-normal season
- 13 to 19 named storms
- 6 to 10 hurricanes
- 3 to 5 major hurricanes (Category 3 or higher)
This heightened activity is attributed to warmer-than-average sea surface temperatures in the Atlantic and Gulf of Mexico, particularly in the Main Development Region between the Canary Islands and the Yucatán Peninsula, which is conducive to the formation of strong storms.
To enhance preparedness and communication, NOAA has introduced several updates for the 2025 season, including:
- Issuing forecasts and storm tracks up to 48 hours before a storm's potential formation.
- Implementing new tools, including an updated storm cone. This tool incorporates inland warnings and nationwide inundation mapping to better visualize flood risks.
- New rip current risk maps when tropical systems are present.
- Upgrading its hurricane forecast system to improve tracking accuracy and intensity predictions by approximately 5%.
As of June 1, no named storms have formed in the Atlantic, marking the fourth consecutive year the season has started without an early storm. Historically, the first named storm typically forms around June 20. The absence of early storms does not necessarily indicate a less active season.
Given the forecasted above-normal activity, residents in hurricane-prone areas are advised to prepare by developing evacuation plans, assembling emergency kits, investing in flood protection, and staying informed through official channels. Early preparation is crucial to ensure safety during the hurricane season.
Why Do Hurricanes Seem Stronger Now? The Role of Climate Change
Over the past few decades, it’s become increasingly clear that hurricanes and storms are not just more frequent - they’re also stronger, wetter, and more destructive. One of the main reasons? Climate change.
Warmer Ocean Temperatures Fuel Storms
Hurricanes draw their strength from warm ocean waters. As global temperatures rise due to human-driven climate change, the oceans absorb much of that heat. Warmer sea surface temperatures give hurricanes more energy to intensify - often rapidly - and to sustain high wind speeds for longer periods. This is why we’re seeing more Category 4 and 5 hurricanes today than we did a few decades ago.
Rising Sea Levels Increase Storm Surge Damage
As glaciers and ice caps melt and oceans warm, sea levels are rising. This means that when a hurricane pushes ocean water onto land (a phenomenon called storm surge) the flooding is more severe. Even a "weaker" storm today can cause more flooding than a stronger storm decades ago because the baseline sea level is higher.
More Rainfall and Slower Storms
A warmer atmosphere can hold more moisture. That means hurricanes now drop significantly more rain, leading to catastrophic inland flooding. At the same time, studies suggest that storms are slowing down, allowing them to hover over communities longer, compounding damage from both wind and water.
If we had asked the question, 'How do hurricanes form?' years ago, the conversation likely wouldn’t have included the increasing frequency of inland storms. This is the reality we’re facing today.
Rapid Intensification is More Common
Climate change has increased the likelihood of rapid intensification, where a storm strengthens dramatically in a short period, sometimes within just 24 hours. This leaves communities with less time to prepare and emergency response teams with greater challenges.
Final Thoughts
Answering this common question, ‘how do hurricanes form?’ helps us better predict, prepare for, and respond to these powerful storms. With climate change warming ocean temperatures, scientists are monitoring how this may influence the frequency and intensity of hurricanes in the years to come.
Furthermore, areas that were once considered low risk for flooding are now experiencing increased flood events from stronger storms. Unfortunately, the reality we’re facing is that the increasing intensity and unpredictability of hurricanes are closely tied to the warming of our planet.