1. Hurricanes
Fall 2016

2. Key Vocabulary
Barometric Pressure—a measure of how heavy or light the air is.
Barometer—a weather instrument that measures barometric pressure
Converge—come together from different directions.
Diverge—to move apart in different directions
Cyclone—area of converging winds circulating around the center of a Low Pressure System.
Anticyclone—opposite of cyclone. Area of diverging winds moving our from the center of a High Pressure System.
Tropical—having to do with an area near the equator where the weather stays warm all year long.

3. Hurricane
A hurricane is a tropical cyclone, or very large and powerful storm, up to 600 miles across, that forms over the ocean and has winds of at least 75 mph (miles per hour).
Hurricanes form over the warm water of the tropics, usually in late summer or early fall.
Hurricanes gather heat energy and moisture from the ocean.
The winds and rains of a hurricane can be very destructive.
Atlantic hurricanes begin as low pressure systems in the Atlantic ocean off of the coast of Africa.

4. Sinking Air v. Rising Air

5. Sinking Air v. Rising Air
Low Pressure System
High Pressure System

6. Low Pressure System L Cloudy Skies Higher Winds Lighter Rising Air
Cyclone—winds converge and rotate around center
Converging winds draw in moisture
Cloudy Skies
Higher Winds

7. High Pressure System H Heavier Sinking Air
Anticyclone—winds diverge from center out
Clear Skies
Light Winds

8. Weather Map

9. What Do Hurricanes Need?
Heat Energy
Moisture
Converging Winds

10. Where Do Hurricanes Form?
Over the Atlantic Ocean
In the Tropics, Near the Equator
They usually begin as low pressure systems, called tropical waves, off the west coast of Africa.

11. Progression
Tropical Disturbance—A Low Pressure System with thunderstorms weather that forms in tropical Atlantic Ocean off the coast of Africa. Sometimes called a Tropical Wave.
Tropical Depression—An area in which winds of up to 38 mph begin to circulate around the center of a Low Pressure System in Atlantic Ocean.
Tropical Storm--A tropical depression with winds between 38 and 73 mph.
Hurricane—Tropical Storm with winds of at least 74 mph.

13. Categories of Hurricanes

14. How Hurricanes Cause Damage
High Winds
Heavy Rain and Flooding
Storm Surge along the beaches

15. Storm Surge
An abnormal rise of water generated by a storm that affects places close to the beach

16. Hurricane Hazel (1954)
One of the most destructive Hurricanes to hit North Carolina
Made landfall as a Category 4 hurricane near the North Carolina-South Carolina border on October 15, 1954
Winds of between mph.
18 foot storm surge along portions of the North Carolina coast.
Heavy rains of up to 11 inches occurred as far northward as Toronto, Canada resulting in severe flooding.
95 deaths and $281 million in damage in the United States
19 deaths in North Carolina .

20. Hurricane Camille (1969)
Made landfall on the Gulf Coast as a Category 5 Hurricane
Winds in excess of 155 mph.
Winds estimated at near 200 mph.
Winds destroyed all wind-recording instruments in landfall area.
23 foot storm surge

22. Other Major Hurricanes
Andrew—1992
Category 4—South Florida
Fran—1996
Category 3—North Carolina
Floyd—1999
Category 3—North Carolina (Extensive Flooding)

23. Hurricane Fran (1996)

24. Hurricane Fran (1996)

25. To find out more about hurricanes click on the following link: