HurricanesHurricanes

I. How Hurricanes FormI. How Hurricanes FormA. Start off the coast of Africa as a A. Start off the coast of Africa as a

Low Pressure System or tropical Low Pressure System or tropical disturbancedisturbance

B. Warm tropical water in the Atlantic B. Warm tropical water in the Atlantic evaporates (cools, condenses and evaporates (cools, condenses and creates clouds…a very LARGE creates clouds…a very LARGE MASS of clouds)MASS of clouds)

C. As Trade Winds push across the C. As Trade Winds push across the Atlantic storm picks up power and Atlantic storm picks up power and is upgradedis upgraded

More about formation…More about formation…

1. Tropical Depression- less 1. Tropical Depression- less than 39 mph (63 kph)than 39 mph (63 kph)

2. Tropical Storm- 39 mph- 73 2. Tropical Storm- 39 mph- 73 mph (63 kph-118 kph)- Storm mph (63 kph-118 kph)- Storm is namedis named

3. Hurricane Category 1- 74 3. Hurricane Category 1- 74 mph or 119 kph minimummph or 119 kph minimum

II. Eye of the HurricaneII. Eye of the Hurricane

A. Eye- calm center of a A. Eye- calm center of a hurricanehurricane

B. Eye wall- ring of clouds B. Eye wall- ring of clouds surrounding the eye making up surrounding the eye making up the strongest part of the stormthe strongest part of the storm

1. Strongest Winds1. Strongest Winds

2. Heaviest Rain2. Heaviest Rain

III. Hurricane MovementIII. Hurricane Movement

A. Hurricanes usually last a A. Hurricanes usually last a week or longerweek or longer

B. Pushed West by the easterly B. Pushed West by the easterly Trade WindsTrade Winds

C. Usually turns and is pushed C. Usually turns and is pushed East by the Prevailing East by the Prevailing WesterliesWesterlies

IV. Loss of PowerIV. Loss of Power

Away from warm, moist Away from warm, moist airair

A. Passes over landA. Passes over land

B. Moves into colder B. Moves into colder waterwater

VI. Hurricane DamageVI. Hurricane DamageA. High Waves caused by strong windsA. High Waves caused by strong winds

B. Severe Flooding caused by heavy B. Severe Flooding caused by heavy rainrain

C. Wind DamageC. Wind Damage

D. Storm Surge- a “dome” of water D. Storm Surge- a “dome” of water that sweeps across the coastthat sweeps across the coast

1. high winds1. high winds

2. very low pressure2. very low pressure

VI. Hurricane SafetyVI. Hurricane SafetyA. Hurricane Watch- hurricane conditions A. Hurricane Watch- hurricane conditions

are possible in your area within the are possible in your area within the next 36 hours (prepare to evacuate)next 36 hours (prepare to evacuate)

B. Hurricane Warning- hurricane B. Hurricane Warning- hurricane conditions are expected within 24 conditions are expected within 24 hours (evacuate the area immediately)hours (evacuate the area immediately)

C. Evacuate- temporarily leave the areaC. Evacuate- temporarily leave the area

VII. Additional InformationVII. Additional InformationAA. Saffir-Simpson . Saffir-Simpson

Scale- used to Scale- used to measure measure hurricanes based hurricanes based on wind speed on wind speed and damageand damage

1. Storm can be 1. Storm can be several hundred several hundred miles acrossmiles across

2. Eye is less 2. Eye is less than 100 miles than 100 miles acrossacross

B. Names in different parts of the worldB. Names in different parts of the world

1. Hurricane- Northern 1. Hurricane- Northern

Hemisphere in the Atlantic Hemisphere in the Atlantic

Ocean and Eastern Pacific Ocean and Eastern Pacific

(North America)(North America)

2. Typhoon- Northern Hemisphere 2. Typhoon- Northern Hemisphere Pacific Ocean (Eastern Asia)Pacific Ocean (Eastern Asia)

3. Cyclone- Southern Hemisphere, 3. Cyclone- Southern Hemisphere, Indian and Pacific Oceans (Australia, Indian and Pacific Oceans (Australia, Africa and India)Africa and India)

C. June-November is hurricane seasonC. June-November is hurricane season

http://www.youtube.com/watch?http://www.youtube.com/watch?v=O0MkIi_KvL8v=O0MkIi_KvL8