Unit Study Guide on Unit Study Guide on Thunderstorms, Tornadoes, Thunderstorms, Tornadoes,

and Hurricanes.and Hurricanes.

Dominique BeckerDominique BeckerED 205-ED 205-0909

April 18, 2008April 18, 2008

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• Thunderstorms• Tornadoes• Hurricanes• Videos• About the Author• Story Board• Resources

ThunderstormsThunderstorms

What Makes a Thunderstorm?What Makes a Thunderstorm?

• Moisture: cloud formation & rain

• Unstable air: relatively warm air rises rapidly

• Lifting: from sea breezes and mountain interaction

Three Types of ThunderstormsThree Types of Thunderstorms

• Air Mass – Result of localized convection in an unstable

air mass• Frontal

– Form right along or just ahead of a cold front• Orographic

– This type of storm is the result of air that is forced upward by a mountain

Thunderstorm FactsThunderstorm Facts

• Every thunderstorm produces lightning

• Heavy rain can lead to flash flooding

• Strong winds, hail, and tornadoes may be associated with thunderstorms

Important Terms for ThunderstormsImportant Terms for Thunderstorms

• A Severe Thunderstorm Watch can be issued by the National Weather Service station– This type of storm has winds of at least 58

mph or hail at least ¾ inch in diameter • A Severe Thunderstorm Warning is issued

when a severe thunderstorm has actually been observed

Thunderstorm Safety TipsThunderstorm Safety Tips

• Go inside and stay away from windows, doors, and porches

• Stay away from trees and out of boats • Avoid plumbing fixtures and contact with

electrical fixtures• Stay off the phone!

TornadoesTornadoes

What is a Tornado?What is a Tornado?• A tornado is a violently rotating column of

air extending between, and in contact with, a cloud and the surface of the earth

• Tornadoes can come one at a time or in clusters

• They can also vary in size, length, width, direction of travel, and speed

How Do You Measure a Tornado?How Do You Measure a Tornado?

• Since February 1, 2008 tornadoes have been measured based on the Enhanced Fujita Scale (EF)

• This scale helps determine the speed of a tornado from weakest to strongest

The Enhanced Fujita ScaleThe Enhanced Fujita Scale

EF 0 65 to 85 MPHEF 1 86 to 110 MPHEF 2 111 to 135 MPHEF 3 136 to 165 MPHEF 4 166 to 200 MPHEF 5 Over 200 MPH

When and Where Do Tornadoes When and Where Do Tornadoes Occur?Occur?

• Tornadoes can occur in any state and any time of year

• They typically occur from March to August• The most common tornadoes are in “Tornado

Alley”• “Tornado Alley” - Arkansas, Iowa, Kansas,

Louisiana, Minnesota, North Dakota, Ohio, Oklahoma, South Dakota, and Texas

Important Terms for TornadoesImportant Terms for Tornadoes

• Tornado Watch: weather conditions are likely for tornadoes to form in our area

• Tornado Warning: A tornado has been sighted in our area

Tornado Safety TipsTornado Safety Tips• Seek shelter immediately when a tornado

warning is issued– Underground shelter is best– If not available, find an inside room, hallway,

or closet on the lowest floor and away from windows

• Listen to the radio or watch TV for updates on the storm

HurricanesHurricanes

What is a Hurricane?What is a Hurricane?

• A hurricane is an intense tropical weather system that has a well-defined circulation and sustained winds of 74 MPH or higher

How Do Hurricanes Form?How Do Hurricanes Form?

• They form when they gather heat and energy through contact with warm ocean waters

• Water evaporates from the water and the moisture produces a storm

• They can also form when a wind pattern occurs near the surface of the ocean and spirals inward

Storms Associated with HurricanesStorms Associated with Hurricanes

• Tropical Depression– An organized of clouds and thunderstorms at

low level circulation with winds at a maximum of 39 mph

• Tropical Storm– An organized system of strong thunderstorms

with winds between 39 to 73 mph

When and Where Do Hurricanes When and Where Do Hurricanes Occur?Occur?

• Hurricanes can occur during any time of the year

• Hurricane season is from June 1st to November 30th

• They can form in the Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern Pacific Ocean

How Do You Measure a Hurricane?How Do You Measure a Hurricane?

• Hurricanes are measured by their speed and it is split into categories

• The categories range from one to five, with one being the weakest and five being the strongest

• The classification of hurricane systems is called the Safir-Simpson Hurricane Scale

Safir-Simpson Hurricane ScaleSafir-Simpson Hurricane Scale

Category One 74 to 95 MPHCategory Two 96 to 110 MPHCategory Three 111 to 130 MPHCategory Four 131 to 155 MPHCategory Five Winds greater then 155

MPH

Note: Hurricanes of Category Three or above are considered major hurricanes.

Why Do Hurricanes Have Names?Why Do Hurricanes Have Names?

• Hurricanes are named to help identify and keep track of storms as they move across the ocean

• Atlantic hurricanes might have Spanish, French, or English names since they come in contact with the borders

• Hurricanes are named alphabetically by the National Weather Service

Why Do Hurricanes Have Names? (2/2)Why Do Hurricanes Have Names? (2/2)

• In 1953, the National Weather Service began using female names

• In 1979, they began to use both men and women’s names

Important Hurricane TermsImportant Hurricane Terms

• A Hurricane Watch occurs when a hurricane is possible within 36 hours– The storm is being tracked to predict where it

may hit• A Hurricane Warning is issued when it the

storm is expected to hit within 24 hours– Evacuation may be needed

Hurricane Safety TipsHurricane Safety Tips• Know if the location you are in is a safe zone or

whether evacuation may be needed• Protect windows and glass with plywood• Turn off utilities• Have a supply kit including first aid, water,

canned goods, battery powered radio, blankets, etc.

• After evacuation, do not return until it has been declared safe

VideosVideos

• Watch a thunderstorm video!Or

• Watch a tornado video!Or

• Watch a hurricane video!

Thunderstorm VideoThunderstorm Video

Tornado VideoTornado Video

Hurricane VideoHurricane Video

Story BoardStory Board

About the AuthorAbout the Author

• My name is Dominique Becker, a sophomore currently attending Grand Valley State University

• I am studying Elementary Education (Integrated Science) and plan to become a middle school Science Teacher

ResourcesResources

• http://facstaff.gpc.edu/~pgore/Earth&Space/GPS/storms-hurricanes-tornadoes-thunderstorms.html

• www.weather.com• http://www.ens-newswire.com/ens/aug2007/200

70830_thunderstorm.jpg• http://rst.gsfc.nasa.gov/Sect14/tornado.jpg• http://www.prisonplanet.com/Pictures/

Oct05/141005hurricane.jpg