HurricanesHurricanes

Earth ScienceEarth Science

Mr. DoeMr. Doe

Hurricane SeasonHurricane Season

Hurricane season in the Atlantic Ocean Hurricane season in the Atlantic Ocean officially runs from June 1officially runs from June 1stst to November to November 3030thth..

Every year scientists try to predict the Every year scientists try to predict the number of active storms that will occur. number of active storms that will occur. Sometimes their predictions are right and Sometimes their predictions are right and sometimes they aren’t.sometimes they aren’t.

The 2008 Hurricane SeasonThe 2008 Hurricane Season

The National Oceanic and Atmospheric The National Oceanic and Atmospheric Administration (NOAA) predicted an above Administration (NOAA) predicted an above average season with 12 to 16 storms, 6 to average season with 12 to 16 storms, 6 to 9 hurricanes, and 2 to 5 major hurricanes on 9 hurricanes, and 2 to 5 major hurricanes on May 22.May 22.

So far there have been 10 named storms: 4 So far there have been 10 named storms: 4 tropical storms and 5 hurricanes.tropical storms and 5 hurricanes.

Hurricane ClassificationHurricane Classification

Storms are classified Storms are classified using the Saffir-using the Saffir-Simpson scale.Simpson scale.

Saffir-Simpson Hurricane Scale

Category Wind Speed Storm Surge

mph(km/h)

ft(m)

5≥156

(≥250)>18

(>5.5)

4131–155

(210–249)13–18

(4.0–5.5)

3111–130

(178–209)9–12

(2.7–3.7)

296–110

(154–177)6–8

(1.8–2.4)

174–95

(119–153)4–5

(1.2–1.5)

Additional Classifications

Tropical Storm

39–73(63–117)

0–3(0–0.9)

Tropical Depressio

n

0–38(0–62)

0(0)

Life Cycle of a HurricaneLife Cycle of a Hurricane

Hurricanes begin over the Atlantic Ocean Hurricanes begin over the Atlantic Ocean between 5between 5º and 20º North latitude.º and 20º North latitude.

The water temperatures are very warm The water temperatures are very warm causing a lot of evaporation.causing a lot of evaporation.

As the warm moist air rises it cools off and As the warm moist air rises it cools off and releases the energy used during releases the energy used during evaporation. This causes the storm to grow evaporation. This causes the storm to grow larger and stronger.larger and stronger.

Life Cycle of a HurricaneLife Cycle of a Hurricane

The warm air causes low pressure to form.The warm air causes low pressure to form.

This low pressure is called a This low pressure is called a tropical tropical depressiondepression..

A tropical depression has wind speeds from A tropical depression has wind speeds from 0-38 mph.0-38 mph.

Life Cycle of a HurricaneLife Cycle of a Hurricane

The prevailing winds (the NE Trade Winds) The prevailing winds (the NE Trade Winds) push the tropical depression to the west.push the tropical depression to the west.

As the storm moves west over the warm water As the storm moves west over the warm water it continues to grow in size and strength.it continues to grow in size and strength.

As wind speeds increase the storm’s As wind speeds increase the storm’s classification changes from tropical depression classification changes from tropical depression to tropical storm to hurricane.to tropical storm to hurricane.

Hurricane NamesHurricane Names 2008 Hurricane Names2008 Hurricane Names

ArthurArthurBerthaBerthaCristobalCristobalDollyDollyEdouardEdouardFayFayGustavGustavHannaHannaIkeIkeJosephineJosephineKyleKyleLauraLauraMarcoMarcoNanaNanaOmarOmarPalomaPalomaReneReneSallySallyTeddyTeddyVickyVickyWilfredWilfred

Hurricane names run Hurricane names run alphabetically.alphabetically.

There are six lists of names There are six lists of names that the National Weather that the National Weather Service uses. These lists Service uses. These lists rotate and names of rotate and names of extremely damaging storms extremely damaging storms are retired from the lists.are retired from the lists.

Life Cycle of a HurricaneLife Cycle of a Hurricane

As the storm moves west its path will bend As the storm moves west its path will bend toward the right. This is caused by the Coriolis toward the right. This is caused by the Coriolis Effect.Effect.

Storms will travel faster and in more of a Storms will travel faster and in more of a straight line over warmer water. They will slow straight line over warmer water. They will slow down when they travel over colder water and down when they travel over colder water and their paths will curve more. their paths will curve more.

Life Cycle of a HurricaneLife Cycle of a Hurricane

Storms will die out (or lose strength) when they Storms will die out (or lose strength) when they travel over colder water and over land.travel over colder water and over land.

As a storm dies out, its wind speeds will As a storm dies out, its wind speeds will decrease. As wind speed decreases, the decrease. As wind speed decreases, the storm will be “downgraded”. A hurricane will storm will be “downgraded”. A hurricane will be downgraded to a tropical storm and a be downgraded to a tropical storm and a tropical storm will be downgraded to a tropical tropical storm will be downgraded to a tropical depression.depression.

Tropical Storm / Hurricane Tropical Storm / Hurricane HannaHanna

Tropical Storm / Hurricane Tropical Storm / Hurricane HannaHanna

Tropical Storm / Hurricane Tropical Storm / Hurricane HannaHanna

Hurricane Ike – Sat. 9/6/2008Hurricane Ike – Sat. 9/6/2008

Hurricane Ike - InfraredHurricane Ike - Infrared

Hurricane Ike – Monday 9/8/2008Hurricane Ike – Monday 9/8/2008

Hurricane Ike – Infrared (Mon.)Hurricane Ike – Infrared (Mon.)

Tropical Storm JosephineTropical Storm Josephine

Tropical Storm JosephineTropical Storm Josephine

Historical Hurricanes - 2007Historical Hurricanes - 2007

Historical Hurricanes - 2006Historical Hurricanes - 2006

Historical Hurricanes – 2005Historical Hurricanes – 2005

Historical Hurricanes – 2004Historical Hurricanes – 2004

Historical Hurricanes – 2003Historical Hurricanes – 2003