1. Hurricanes

2. What is a storm? Air is heated up creating low pressure Air rises
Cools and condenses
Air from high pressure move to low pressure
This air rises, “fueling” the storm
Winds push the storm out to sea

3. What is a hurricane storm system low pressure center
surrounding thunderstorms.
Hurricanes strengthen over oceans
What they are called depends on their location of formation.
Hurricane in the Atlantic ocean
Tropical cyclone in the Pacific and Indian oceans
Typhoon in the Northwest Pacific ocean
Willy Willies in Australia

4. How they form Begins with a thunderstorm blown out to sea.
Then it must have:
1. ocean waters must be warm to put heat and moisture into the overlying atmosphere
2. moisture from sea water evaporation must combine with that heat and energy
3. a wind pattern

5. die out over land masses destructive force lie in their storm surges.
hurricane takes in air from surrounding areas this new air replaces the lost old air
die out over land masses
destructive force lie in their storm surges.
also have some destructive force in their winds and rains.
The hurricanes spin counter clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere*
*Due to coriolis effect, when rising it reverses
*Winds become slower toward the poles theory

6. How we measure hurricanes
Saffir–Simpson Hurricane Scale
Category
Wind speed
Storm surge
mph (km/h) (kn)
ft. (m)
Five
≥ 157 (≥ 252 (≥ 137)
> 18 (> 5.5)
Four
130–156 (209–251) (113–136)
13–18 (4.0–5.5)
Three
111–129 (178–208) (96–112)
9–12 (2.7–3.7)
Two
96–110 (154–177) (83–95)
6–8 (1.8–2.4)
One
74–95 (118–153) (64–82)
4–5 (1.2–1.5)
Additional classifications
Tropical storm
39–73 (63–117) (35–63)
0–3 (0–0.9)
Tropical depression
0–38 (0–62) (0–34)
0 (0)
A hurricane is measured using the Saffir-Simpson scale
We measure their intensity through their wind speed and storm surge height.
A storm surge is the rise of water that is associated with an incoming storm.

7. Their anatomy Eye- low-pressure, center of the hurricane
Eye wall- area around the eye, includes the most violent storms
Rain Bands- thunderstorm bands that circulate out from the eye
Coriolis effect- natural phenomenon that causes winds to veer right in the northern hemisphere and left in the southern due to spin
Rain shields- completely solid or nearly solid areas of rain that are heavier the closer to the eye

8. Random facts After god Huracan
Can release power up to the amount of a couple of Atomic bombs
Hurricane season during summer
Naming
Originally only phonetic names
Then only women
Changed to alternate
Used to be named after saints

9. Their effect on waters Aquatic environments
Cause sediment erosion removing many habitats/homes
Salt water intrusion killing many freshwater fish
Flood waters filled with many industrial products that poison organisms
Fisheries can be totally destroyed by winds
Effect on coastal ocean is the scraping of the bottom due to large waves
Little effect on open ocean due to tidal flow
Normally can rebound in 3 years

10. Their effect on land Terrestrial environments
Wetlands destroyed the most due to the erosion or shift of barrier islands
Mangrove forests destroyed by winds, destroying many animal’s habitats
Sea grass beds, which are for feeding and nesting are often destroyed
Also causes massive damage to human structures

11. Examples
Bhola cyclone in Bangladesh killed 300,000 to 500,000 though only Cat. 3
Galveston hurricane in Galveston, TX killed 6,000 cost 500 million dollars, destroyed 3,600 Cat. 4
Hurricane Katrina- Cat. 5, 1,833 killed, costliest hurricane in U.S. history 108 billion dollars

12. Detection/Prevention
Aircrafts- fly near the hurricane to collect information
Ships- measure the heat of the sea around the storm also collect information.
Satellites- take pictures showing the direction and speed of the storm also measure temperature and rainfall in and estimate its strength and course.

13. Detection/Prevention
Doppler radar- show location and intensity of precipitation and the wind motions
Levee prevent the floods from coming
Reinforcing buildings help with strong winds

14. Questions
If I was on the southern coast of Brazil in fall should I be worried about being hit by a hurricane?
Where are the most violent storms?
How do hurricane’s destroy ocean life in the coastal waters?
What is the name of the scale we use to measure hurricanes?
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