One of the planet's strongest storms is a hurricane.But how does it form?
A hurricane is a large and powerful storm with winds that can reach up to 200 hundred miles per hour.
From space, they look like a giant spinning pinwheel hundreds of miles across.
Clouds rotating around the center where conditions are clear and calm. This is called" the eye".
Hurricanes form in water,that's at least 80 degrees in the Atlantic ocean,most hurricanes form when the water is warmest between June and November.
The water warms the air above it, causing it to rise.As the air rises, clouds and thunderstorms form.To replace the rising air, winds at the Surface start to rush in.
This air also rises and forms even more clouds, making the storm bigger and stronger.
The winds get faster and faster，and when they reach 39 miles per hour.It's a tropical storm ,and gets a name.
When the winds hit 74 miles per hour，it's officially a hurricane.
As long as hurricanes stay out over the ocean, they are pretty harmless.
But sometimes winds can push the hurricanes toward land,they might curve to the north and miss us, but other times they hit the coastline with heavy rain, flooding and strong winds.
spinning 旋转的
pinwheel 玩具风车
rotate 旋转
tropical storm 热带风暴
coastline 海岸线
