2. Objectives Identify the conditions required for tropical cyclones to form. Describe the life cycle of a tropical cyclone. Recognize the dangers of hurricanes. Tropical Storms Section 13.3

3. Tropical Storms Section 13.3 Review Vocabulary Coriolis effect: caused by Earth’s rotation, moving particles, such as air, are deflected to the right north of the equator, and to the left south of the equator Normally peaceful, tropical oceans are capable of producing one of Earth’s most violent weather systems—the tropical cyclone.

4. New Vocabulary Tropical Storms Section 13.3 tropical cyclone eye eyewall Saffir-Simpson hurricane scale storm surge

5. Overview of Tropical Cyclones Tropical Storms Section 13.3 During summer and fall, the tropics experience conditions ideal for the formation of large, rotating, low-pressure tropical storms called tropical cyclones.

6. Tropical Storms Section 13.3 Overview of Tropical Cyclones Favorable conditions for cyclone formation exist in all tropical oceans except the South Atlantic Ocean and the Pacific Ocean off the west coast of South America( because the waters are not warm enough). Cyclone location

7. Tropical Storms Section 13.3 Overview of Tropical Cyclones Tropical cyclones require two basic conditions to form: 1.an abundant supply of warm ocean water and 2.some sort of mechanism to lift warm air and keep it rising. Cyclone formation- conditions.

8. Cyclone formation - stages 1. tropical disturbance – Low pressure above ocean waters. 2. tropical depression - the disturbance acquires a cyclonic circulation around the low pressure. 3. tropical storm - wind speeds around the low- pressure exceed 65 km/h. 4. cyclone/hurricane - If air pressure continues to fall and winds reach at least 120 km/h. Cyclone dissipates on reaching land or cold waters.

9. Tropical Storms Section 13.3 Overview of Tropical Cyclones Once winds reach at least 120 km/h, another phenomenon occurs—the development of a calm center of the storm called the eye. The eye of the cyclone is a span of 30 to 60 km of calm weather and blue sky. Cyclone formation

10. Overview of Tropical Cyclones Cyclone formation The strongest winds in a hurricane are usually concentrated in the eyewall—a tall band of strong winds and dense clouds that surrounds the eye. Tropical Storms Section 13.3

11. Tropical Storms Section 13.3 Overview of Tropical Cyclones Tropical cyclone movement Like all large-scale storms, tropical cyclones move according to the wind currents that steer them.

12. Tropical Storms Section 13.3 Hurricane Hazards The Saffir-Simpson hurricane scale classifies hurricanes according to 1.wind speed, 2.potential for flooding due to the effect on the height of sea level, 3.potential for property damage.

13. Tropical Storms Section 13.3 Hurricane Hazards Damage Hurricanes can cause extensive damage, particularly along coastal areas, which tend to be where human populations are the most dense.

14. Tropical Storms Section 13.3 1. Winds 2. storm surge occurs when hurricane-force winds drive a mound of ocean water toward coastal areas where it washes over the land. 3.Torrential rain. Hurricane Hazards

15. Tropical Storms Section 13.3 The National Hurricane Center issues a hurricane warning at least 24 hours before a hurricane is predicted to strike. Awareness, combined with proper safety precautions, has greatly reduced death tolls associated with hurricanes in recent years. Hurricane Hazards Hurricane advisories and safety

16. CH Normally peaceful, tropical oceans are capable of producing one of Earth’s most violent weather systems—the tropical cyclone.  Cyclones rotate counterclockwise in the northern hemisphere.  Cyclones are also known as hurricanes and typhoons. Section 13.3 Tropical Storms Study Guide Key Concepts

17. CH  Cyclones go through the same stages of formation and dissipation as other storms.  Cyclones are moved by various wind systems after they form.  The most dangerous part of a tropical cyclone is the storm surge.  Hurricane alerts are given at least 24 hours before the hurricane arrives. Section 13.3 Tropical Storms Study Guide Key Concepts

18. CH At what latitudes do tropical cyclones usually form? a. between 0  and 5  b. between 5  and 30  c. between 30  and 50  d. between 50  and 70  13.3 Section Questions The Nature of Storms

19. CH What weather condition usually exists within the eye of a hurricane? a. high wind b. calm wind c. tornadoes d. lightning 13.3 Section Questions The Nature of Storms

20. CH What is the source of a hurricane’s energy? 13.3 Section Questions The Nature of Storms Answer: A hurricane’s energy comes from the warm water over which it develops. As ocean water evaporates, some heat is taken from the ocean. The water vapor then rises high into the atmosphere. The heat that was taken from the ocean is released to the atmosphere as the water vapor condenses.