Hurricanes

Hurricane Learning Targets

You will be able to…

• Describe ingredients for hurricane formation

• Describe stages in hurricane development

• Diagram the anatomy of a hurricane

• Predict the path of an Atlantic hurricane

• Describe hazards associated with hurricanes

• Explain the naming system for hurricanes

Hurricane Ingredients

1. Warm water (80ºF +)

2. Low pressure center (CCW flow)

Why do most hurricanes start out moving EAST to WEST?

1. Tropical Depression (TD)

Characteristics

• Poorly organized

• Winds < 39 mph

• Pressure drops L

http://earthobservatory.nasa.go

v/NaturalHazards/Archive/Oct2

002/

trop_dep_14_15oct02.jpg

Hurricane Development

2. Tropical Storm (TS)

• pressure decreases

• winds speed increase

(39 -74 mph)

• Obvious CCW spiral

pattern

• Assigned a name

– ex. TS Katrina (‘05)

http://earthobservatory.nasa.gov/NaturalHazards/Archive/Sep2002/

Mekkhala_TMO2002268.jpg

3. Hurricane

• wind speeds increase

( > 74 mph)

• pressures continues to

drop

• hurricane keeps name

http://www1.ncdc.noaa.gov/pub/data/images/hurr-isabel-20030912-1915-g12vis.jpg

Hurricane Season • June 1- November 30

• Peak: Why not June? Why July-Aug??

http://www.nhc.noaa.gov/gifs/peakofseason.gif

http://www.srh.noaa.go

v/jetstream/tropics/tc_a

tlclimo_pct.htm

TS Olga (12/2007)

Westerly Winds

Trade Winds

Hurricane Weakening

• storm reaches cooler waters

• storm make landfall

– its energy source (warm water) is

missing

• they collide with other systems (H, L)

Hurricane Hugo

How did this

hurricane make it

so far north?

How did Irene

make it so far

north?

LOW PRESSURE

OCEAN WATER

PULLED UPWARD

Hurricane Damage

• Storm Surge

Storm Surge

• NOT a large wave…but steady rises in sea level

• Storm surge piles atop normal tide waters

• Gently sloping coastlines are most susceptible to storm

surges (see animation)

Gulf Shores, AL (after Ivan ‘04)

Gulf Shores,

Alabama

How did the

engineers

design this

condo with

hurricanes in

mind?

Hurricane Damage

• Storm Surge

• Wind Damage

Hurricane

Michelle 2001

http://homepages.wmich.edu/~cutrim/course/225/AguadoClassnotes/Chpt12/16

Second wind velocity diagram

Hurricane Damage: Strong side vs. weak side

• Which city

experienced the

stronger wind

speeds?

• Explain why:

Hurricane Damage

• Storm Surge

• Wind Damage

• Tornadoes

Hurricane Damage

• Storm Surge

• Wind Damage

• Tornadoes

• Rainfall

Image References & Citations

• ISS Images: http://spaceflight.nasa.gov/gallery/images/station/crew-

9/inflight/ndxpage20.html

• Current Hurricane Info (TWC)

• Current TS Olga (12/07) http://www.cubaweather.org/

• GOES Satellite Images http://www.goes.noaa.gov/

• National Hurricane Center http://www.nhc.noaa.gov/

• Archived Hurricanes http://www.nhc.noaa.gov/HAW2/english/history.shtml#wilma

• http://www.orangebeachcondo.com/ivan_updates.html

• http://www.pensacolasgreatest.com/HurricaneIvan.html