04/18/231Hurricane Basics

A Presentation on Hurricane Basics. Part of the Hurricane Learning Series By Hurricaneville.

04/18/232Hurricane Basics

AGENDA

IntroductionFactors In Hurricane DevelopmentStages Of Hurricane DevelopmentThe Saffir-Simpson ScaleComponents of a HurricaneOrigins of a HurricaneHurricane TracksEffects from a HurricaneNaming of HurricanesCredits

04/18/233Hurricane Basics

Introduction

04/18/234Hurricane Basics

INTRODUCTION

Hurricanes are among the most fiercest forces on earth. They are a vast mass of clouds that form in the tropics, and bring heat to the poles. These tropical cyclones bring high winds, heavy rains, and dangerous tides from the coast to areas farther inland.

04/18/235Hurricane Basics

INTRODUCTION

Hurricanes occur throughout all the tropical regions of the world. Consequently, they are described with different terminology. They are called Typhoons in the Western Pacific, Cyclones in the Indian Ocean and Southern Pacific, and sometimes Willy-Willys in Australia.

04/18/236Hurricane Basics

Factors In Hurricane Development

04/18/237Hurricane Basics

FACTORS IN HURRICANE DEVELOPMENT

Hurricanes can develop into very powerful storms if the conditions in the atmosphere are right. Below are several key factors in hurricane development.First, you need a spin—Tropical Disturbances develop from the convergence of trade winds in the tropics. All tropical systems must have some sort or rotation.Warm water a must---Hurricanes are a vast heat engine that need sea surface temperatures to be at least 80 degrees in order to grow and mature.No shearing allowed—Unlike tornadoes, hurricanes are a vertically stacked system that move from east to west. Therefore, they must have high pressure and light winds aloft.

04/18/238Hurricane Basics

Stages Of Hurricane Development

04/18/239Hurricane Basics

STAGES OF HURRICANE DEVELOPMENT

Hurricanes go through several different stages of development before they reach hurricane status.Tropical Wave--Is the first step toward a hurricane. They are areas of low pressure that lack a closed center of circulation. About hundred of these develop each year in the Atlantic Ocean.Tropical Depression--Develops when a tropical wave develops a closed low level circulation, and wind speeds in excess of 20 knots, or 25 mph.Tropical Storm—Develops when a tropical depression has sustained wind speeds of 35 knots, or 39 mph.Hurricane—Develops when a tropical storm has sustained wind speeds of 65 knots, or 74 mph.

04/18/2310Hurricane Basics

The Saffir-Simpson Scale

04/18/2311Hurricane Basics

THE SAFFIR-SIMPSON

SCALEOnce a tropical system matures to a hurricane, it can continue to strengthen to even greater heights. The stronger the hurricane, the more catastrophic the damage can be upon landfall. Below is the Saffir-Simpson Scale, which is used to measure a hurricane’s intensity and potential for damage.

CategoryCategory WindsWinds PressurePressure DamageDamage

OneOne 74-95 mph74-95 mph >=28.94 in.>=28.94 in. MinimalMinimal

TwoTwo 96-110 mph96-110 mph 28.50-28.91 in.28.50-28.91 in. SignificantSignificant

ThreeThree 111-130 mph111-130 mph 27.91-28.47 in.27.91-28.47 in. SevereSevere

FourFour 131-155 mph131-155 mph 27.17-27.88 in.27.17-27.88 in. ExtremeExtreme

FiveFive >155 mph>155 mph <27.17 in.<27.17 in. CatastrophicCatastrophic

04/18/2312Hurricane Basics

Components Of A Hurricane

04/18/2313Hurricane Basics

COMPONENTS OF A HURRICANE

There are several key components to a mature hurricane: The Eye, Eyewall, Central Dense Overcast, and Outflow. Below is a brief explanation of each.The Eye—Is the center of circulation, and area of lowest pressure in tropical storm or hurricane. It is most notably known as the deceptive area of calm in the storm.Eyewall—It is the solid ring of showers and thunderstorms surrounding the eye. This is where the hurricane’s highest winds are usually located.Central Dense Overcast—The circular mass of embedded showers and thunderstorms in the heart of a hurricane.Outflow—Probably the most critical piece of a hurricane’s machinery. It is the outer fringes of the hurricane where heat energy is released into the atmosphere.

04/18/2314Hurricane Basics

Origins Of A Hurricane

04/18/2315Hurricane Basics

ORIGINS OF A HURRICANE

Hurricanes form in several regions of the Tropical Atlantic. Below is a brief description of each.Gulf of Mexico—This region is the most conducive for hurricane development throughout the year with sea surface temperatures between 85 and 90 degrees.Western Caribbean—This region is where a lot of hurricanes form in the initial and final months of every hurricane season.Cape Verde Islands—This region is commonplace for the development of the classic hurricane that occurs during the peak months of August and September of each hurricane season.

04/18/2316Hurricane Basics

Hurricane Tracks

04/18/2317Hurricane Basics

HURRICANE TRACKS

Hurricanes take several basic routes depending on there origin. Below is a brief description of each.Forming in the Gulf of Mexico, and heading northward into the Southeastern United States.Forming in the Western Caribbean, and moving into Central America, or the Yucatan Peninsula, and then later moving into the Gulf before landfalling again in Northern Mexico, or Southern Texas.Forming near the Cape Verde Islands, and moving West through the Caribbean, and then either making landfall along the Gulf Coast, or Eastern Seaboard of the United States.

04/18/2318Hurricane Basics

Effects From A Hurricane

04/18/2319Hurricane Basics

EFFECTS FROM A HURRICANE

Hurricanes can bring a variety of effects. Some are greater than the others. Below is a brief description of each.Rain—Probably the most underrated of all effects from a tropical storm or hurricane. Amounts can be as high as several feet.Wind—The next most devastating effect behind storm surge, hurricanes can have winds up to and above 200 mph.Tornadoes—Many do not realize it, but hurricanes can produce tornadoes upon landfall. The friction between the storm and land produces a great deal of instability, and thus, Tornadoes.Storm Surge—The most deadly effect from a hurricane, this rising dome of water that accompanies landfall accounts for about 90 percent of all hurricane deaths.

04/18/2320Hurricane Basics

Naming Of Hurricanes

04/18/2321Hurricane Basics

NAMING OF HURRICANES

Tropical Storms and Hurricanes are often referred to by name throughout the world, particularly in the Atlantic Basin.They are named so that it is easier to explain and effectively communicate information on them to residents that could be effected.The National Weather Service began naming tropical storms and hurricanes in 1953 by using names of girls.In 1979, The National Hurricane Center got with the times, and gave tropical storms, and hurricanes boys names as well.The National Hurricane Center has a complete list of current names of tropical storms and hurricanes for the current six year cycle as well as a list of retired names.

04/18/2322Hurricane Basics

Credits

04/18/2323Hurricane Basics

CREDITS

HurricanevilleGreg’s Weather Center

Hurricane CityThe Weather Channel

The National Hurricane CenterRutgers Meteorology Department

World Book EncyclopediaEssentials of Meteorology: An Invitation To The

Atmosphere.The Weather Book

04/18/2324Hurricane Basics

We here at Hurricaneville hoped you enjoyed, and learned a lot from this presentation.