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Hurricane Anatomy & Saffir-Simpson Scale Cheat Sheet
A printable reference covering hurricane anatomy, storm formation, naming, Saffir-Simpson categories, wind speed, storm surge, and hazards for grades 5-11.
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This cheat sheet explains the main parts of a hurricane, how hurricanes form, how storms are named, and how their strength is classified. Students need these ideas to understand weather reports, maps, forecasts, and safety warnings during tropical cyclone season. The reference connects visible storm features, such as the eye and eyewall, to the dangerous conditions people experience on land and at sea. The most important concepts are the hurricane’s structure, the warm ocean conditions needed for formation, and the Saffir-Simpson Hurricane Wind Scale. Hurricanes need warm ocean water, moist air, low wind shear, and rotation from Earth’s spin to organize. The Saffir-Simpson Scale ranks hurricanes from Category 1 to Category 5 using sustained wind speed, but storm surge, flooding rain, and tornadoes can also cause serious damage.
Key Facts
- A hurricane is a tropical cyclone with sustained winds of 74 mph or higher, or 119 km/h or higher.
- The eye is the calm, low-pressure center of a hurricane, and it is usually surrounded by the most violent winds in the eyewall.
- The eyewall contains the strongest winds and heaviest rain because air rises rapidly around the eye.
- Rainbands are curved bands of thunderstorms that spiral into the center and can bring heavy rain, gusty winds, and tornadoes.
- Hurricanes usually form over ocean water at least about 26.5°C, or 80°F, with moist air and low vertical wind shear.
- The Saffir-Simpson Scale uses 1-minute sustained wind speed to assign hurricane categories from 1 to 5.
- Category 1 starts at 74 mph, Category 2 starts at 96 mph, Category 3 starts at 111 mph, Category 4 starts at 130 mph, and Category 5 starts at 157 mph.
- Storm surge is a rise in sea level pushed onshore by hurricane winds, and it is often one of the deadliest hurricane hazards.
Vocabulary
- Hurricane
- A hurricane is a powerful tropical cyclone with sustained winds of at least 74 mph that forms over warm ocean water.
- Eye
- The eye is the relatively calm center of a hurricane where air sinks and pressure is lowest.
- Eyewall
- The eyewall is the ring of intense thunderstorms around the eye where the strongest winds and heaviest rain usually occur.
- Rainband
- A rainband is a curved line of thunderstorms that spirals toward the hurricane’s center.
- Storm Surge
- Storm surge is abnormal sea level rise caused mainly by strong winds pushing ocean water onto land.
- Saffir-Simpson Scale
- The Saffir-Simpson Scale classifies hurricanes from Category 1 to Category 5 based on sustained wind speed.
Common Mistakes to Avoid
- Confusing the eye with the most dangerous part of the storm is wrong because the eye is often calm while the surrounding eyewall has the strongest winds.
- Thinking the Saffir-Simpson category describes all hurricane hazards is wrong because the scale is based on wind speed only, not rainfall, storm surge, or tornado risk.
- Calling every rotating ocean storm a hurricane is wrong because tropical depressions and tropical storms have lower wind speeds, and the name also depends on the ocean basin.
- Ignoring storm surge during a lower-category hurricane is wrong because even a Category 1 or Category 2 storm can cause deadly coastal flooding.
- Assuming a hurricane is safe after the eye passes is wrong because the eyewall can return with strong winds from the opposite direction.
Practice Questions
- 1 A tropical cyclone has sustained winds of 82 mph. Is it a tropical storm or a hurricane, and what Saffir-Simpson category is it?
- 2 A hurricane has sustained winds of 135 mph. What category is it on the Saffir-Simpson Scale?
- 3 Ocean water near a storm is 28°C, the air is moist, and vertical wind shear is low. Are these conditions favorable for hurricane formation? Explain briefly.
- 4 Why can a Category 2 hurricane still be extremely dangerous even though it is not a major hurricane?