HURRICANESThe History, Structure, Development, and

Destruction

Source: http://www.dc.peachnet.edu/~pgore/students/w97/matheson/hpage.htm

Modified from multiple internet sources

What is a hurricane? Violent

cyclonic storm that develops in the tropical region

Wind speeds are > 74 mph

Source: http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=680

Rotation and PressureIn which direction does a hurricane rotate?

COUNTERCLOCKWISE (northern hemisphere)CLOCKWISE (southern hemisphere)

Is the barometric pressure inside the hurricane high or low?

LOW

When is Hurricane Season?

June 1st throughNovember

31st

What is the role of the National Weather Service during hurricane season?

Provides weather information, such as data from satellites

Responsible for issuing watches and warnings to the media and general public

Watch vs. Warning What is the difference between a

Hurricane Watch and a Hurricane Warning? Watch – Tropical storm poses a threat

to coastal areas with 36 hours Warning - Tropical storm conditions

are expected in a coastal area within 24 hours

The Path of Hurricanes

When hurricanes make “landfall” they have come onshore in a certain area. Due to the fact that they are huge storms, the areas adjacent to the actual landfall location are also impacted.

Hurricanes have “paths” in which they travel and move at different speeds over water and land. Once they hit land, they do slow down and weaken. Warm water “feeds” the hurricane and helps them grow larger and stronger.

What conditions must be present for a hurricane to

develop? Warm ocean

temperatures (>80˚ F) up to 60m deep

Little to no wind shear Low pressure system at

least 5˚ North or South of Equator

Rotation caused by winds

Intertropical Convergence Zone I

The ITCZ is an area of low pressure located roughly 5 degrees North and South of the Equator. It is a place where air converges, rises, and condenses (forming clouds). It is the rainiest place on Earth!

Intertropical Convergence Zone II Thunderstorms push off the coast of

Africa and become tropical disturbances (waves)

Intertropical Convergence Zone III

What is the major source of energy fueling a

hurricane?Heat Energy evaporating

from the ocean surface

Source: http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/evap.rxml

Hurricane Anatomy

Source: http://hurricanes.noaa.gov/prepare/structure.htm

Another look at the Structure

Source: http://hurricanes.noaa.gov/prepare/structure.htm

Comparison of Terms Tropical Disturbance

Group of thunderstorms in the tropics that are present for at least 24 hours

Tropical Wave lack of circulation, winds <25 mph and

every direction

Tropical Depressionclosed circulation but disorganized, winds

at least 25 mph

Comparison of TermsTropical Storm

Shower and thunderstorm moves over closed circulation, winds greater than 39 mph

HurricaneEye is developed, winds > 74 mph

Compare the Following

Source: http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hurr/stages/home.rxml

By what two factors is hurricane strength

measured?

Wind Speed

Barometric Pressure

What is the Scale Used to Categorize Hurricanes?

Saffir-Simpson ScaleCategor

yMax Wind

Speed(mph)

Min. Surface Pressure (mb)

Storm Surge m (ft)

1 74-96 > 980 1-1.7 (3-5)2 97-111 979-965 1.8-2.6 (6-8)3 112-131 964-945 2.7-3.8 (9-12)4 132-155 944-920 3.9-5.6 (13-

18)5 > 155 < 920 > 5.7 (>19)

Source: http://kids.earth.nasa.gov/archive/hurricane/saffir-simpson.html

What causes the damage in a hurricane?

WindsFloodingStorm Surge

What is a storm surge? Large wall or dome

of water that rushes into the coastline as a result of a hurricane making landfall

To the right are the areas affected by high storm surges

Souce: http://www.wkrg.com/hurricanecenter/surge/SE.jpg

What destroys a hurricane? Strong vertical winds Cold water Movement over land

FrictionLack of moisture

What are the five costliest hurricanes in the United

States?1. Hurricane Katrina – 20052. Hurricane Andrew – 19923. Hurricane Hugo – 19894. Hurricane Fran – 19965. Hurricane Opal – 1995

Hurricane Trivia: Costliest StormHurricane Trivia: Costliest StormHurricane Katrina of the 2005 Atlantic hurricane season was the costliest

hurricane. The total damage from Katrina is estimated at $81.2 billion

Information from Wikipedia Animated photo from CIMSS

Explain why the majority of the costliest storms are relatively

recent Damage is a

result of development

There are more developed areas and possessions than in the past

Source: http://www.nhc.noaa.gov/1992andrew.html

What are the five deadliest hurricanes in the United

States?1. Galveston – 19002. Southeast Florida – 19283. Florida Keys – 19194. New England – 19385. Florida Keys – 1935

Explain why the deadliest storms were longer ago.

Lack of instrumentation to predict and track storms

People were not warned of the incoming danger

Source: http://www.1900storm.com/photographs/photo10.html

Results of the Galveston Hurricane

Hurricane Trivia: Deadliest StormHurricane Trivia: Deadliest Storm The Galveston Hurricane of 1900

made landfall on the city of Galveston, Texas on September 8, 1900. It had estimated winds of 135 mph (215 km/h) at landfall, making it a Category 4 storm on the Saffir-Simpson Hurricane Scale.

Picture and information Source: Galveston Hurricane of 1900 - Wikipedia, the free encyclopedia

During he 1900 Storm: Galveston, Texas, 6,000 people died and it destroyed the city.

AndreaBarryChantalDeanErinFelixGabrielleHumbertoIngridJerryKarenLorenzoMelissaNoelOlgaPabloRebekahSebastienTanyaVanWendy

An example list:

•In 1953 the National Weather Service began naming storms after women.

•In 1979, men’s names were added to the list of hurricane names.

• In the Atlantic, there are 6 lists of names that are recycled.

• In the case of storms so devastating that reusing the name is inappropriate, the name is taken off the list and another name is used to replace it. The name “Katrina” is one that will be removed from the list.

Hurricane Naming System – Why do they have names anyway?

What are the names of the 2002 Hurricanes?

Arthur Hanna OmarBertha Isidore Paloma

Cristobal Josephine ReneDolly Kyle Sally

Edouard Lili TeddyFay Marco Vicky

Gustav Nana WilfredSource: http://www.hurricanewarning.net/coordinates.html

How has a hurricane affected you personally?

Damage to your house from wind?

Damage from flooding?

Destroyed vacation house?

Damage to family members’ homes?

http://cindi.usgs.gov/cindi/hazard/event/floyd/ncflood/mediums/img023.jpg

Mrs. Parker’s

Old House

Final Water Level

Flooding of Tar River as result of Hurricanes Dennis and Floyd

DocksideTar RiverEstates

Damage to Greenville Extensive Flooding

Extended Power outages

Flood Related Deaths

Property Damage

US 264 Bridge

Source: http://cindi.usgs.gov/cindi/hazard/event/floyd/ncflood/mediums/img022.jpg

Damage to Greenville

Source: http://www.guc.com/about/floyd.htm

More cool stuff to check out…

Hurricane Damage I

Hurricane Damage II

Hurricane Damage III

Hurricane Damage IV

Think about this. How do you think technology has changed Hurricane awareness and safety? The map on the left is a map from Hurricane Hilda in 1964. The map on the right is a map of Hurricane Rita in 2005. If the technology now available had existed for the 1900 Galveston Hurricane, could the outcome have been different? How? Why? Explain your answer to the class or write a paragraph about it.

Has technology changed hurricane forecasting?

Protection Listen to warnings Take all warnings seriously Follow evacuations Prepare Food and Water for extensive power outages

Source: http://www.dc.peachnet.edu/~pgore/students/w97/matheson/hpage.htm

THE END