A heat engine over warm water
How Do Hurricanes Form?
A hurricane runs on warm ocean, turning evaporated water into wind.
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Step 1 of 5
It needs ocean water above about 26°C.
Only warm sea evaporates fast enough to fuel the storm. This is why hurricanes form in late summer and die within hours over land.
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Step 2 of 5
Rising moist air leaves low pressure behind.
Warm humid air lifts off the sea surface. As it rises, surface pressure falls, and surrounding air rushes in to replace it.
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Step 3 of 5
Condensation releases the real energy.
When that vapour condenses into cloud, it gives back the heat that evaporated it. That heat warms the column further and drives it higher.
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Step 4 of 5
It becomes a loop that feeds itself.
Stronger rising means lower pressure, which pulls in more warm moist air, which releases more heat. The storm intensifies itself.
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Step 5 of 5
Earth's spin gives it the eye.
Rotation curves the inflowing air into a spiral. At the centre, air sinks instead of rising — the calm, clear eye.
A hurricane releases energy comparable to hundreds of times the world's electricity generation.
The short version
Hurricanes are self-feeding heat engines: warm sea evaporates, condensation releases heat, and the storm spins itself stronger.
Try it yourself
Track a hurricane's path against sea temperature maps online. It strengthens over warm water and collapses over cold or land.
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