IntroIntro Objective 04/27/12 Describe the formation of hurricanes. What is the difference between a hurricane, a typhoon, and a cyclone?

Hurricanes  Tropical cyclone  Massive tropical storm that forms over warm ocean water, with extremely strong winds spiraling around a center of low air pressure  Same storm, different names:  Hurricanes  Typhoons  Cyclones

Hurricanes  Where?  Form over warm ocean waters near the equator  Hurricanes that effect the US begin off the west coast of Africa!

Hurricanes  Typhoon  Cyclone  Term used for a tropical cyclone in the Pacific Ocean near Asia  Term used for tropical cyclone in Indian Ocean or South Pacific Ocean

Hurricanes

 Hurricane  Term used for tropical cyclone that forms over warm ocean water in the North Atlantic or eastern North Pacific

Hurricanes  Structure  Coriolis Effect  Northern Hemisphere  spin counterclockwise  Southern Hemisphere:  Spin clockwise  Spiraling of winds due to the Earth’s rotation

Hurricanes  Eye  Eyewall  Circular region located at the center of a hurricane  Usually has calm weather  Warm air is rising, creating a low pressure zone  Region of tall clouds, heavy rains, and strong winds surrounding the eye  Most severe rain and winds in a hurricane

Hurricanes  Rainbands  Region of heavy thunderstorms beyond the eyewall that spiral outward from the center of a hurricane

Hurricanes  Formation 1. Energy source:  Warm water  As water vapor evaporates it carries heat energy into the atmosphere 2. Water vapor condenses, releasing the heat energy  Rising air spirals, creating the eye (low pressure zone)

Hurricanes  Formation (cont.)3. Thunderstorms become organized and cluster together  As they strengthen they rotate, eventually creating a hurricane

Hurricanes  Death of a Hurricane  Wind shear  Cool water  Move over land  Change in wind speed and/or wind direction at different heights in the atmosphere  Cool ocean water does not evaporate easily  Lack of warm water for the hurricane

Hurricanes  Death of a Hurricane  Saharan Air Layer  Hot, cry, dusty air layer that forms over North Africa in the summer and affects the formation of hurricanes in the Atlantic Ocean

Hurricanes  Saffir Simpson Scale  Measures wind speed and how strong the hurricane is

Hurricanes  Facts  Average 6-10 per year  Hurricane Season:  July - September  Circular shape  Average diameter = 300miles  Ocean water has to be at least 80˚F to create a hurricane

Hurricanes  Tracking  Satellites  Airplanes  Gathers large amounts of data over wide regions  Can get directly inside a hurricane to gather data

Hurricanes  Dropsonde  Weather detection device designed to be dropped from a hurricane hunter aircraft to collect data on tropical storm conditions as the device falls to Earth  Collects data on global position, air pressure, temperature, humidity, wind speed, and wind direction

Hurricanes  Doppler Radar  Enhanced radar that can detect storm location, intensity and amount of precipitation, wind speed and wind direction, rotation patters and other valuable data

Hurricanes  Path  Travel from East to West while strong  Reverse when weak

Katrina: Path, 2005

Hugo: Path, 1989

Andrew: Path 1992

Camille: Path 1969

NY Hurricane: Path, 1938

Hurricanes  Record Holder  Typhoon Tip, 1979  1380 miles wide  Wind speeds over 190 mph

Hurricanes  Hurricane Safety  Evacuate!!!  Staying?  Have disaster kit containing: Food Water Basic first aid Flashlight  Board up windows  Stay indoors

Objective 04/27/12 OutroOutro Describe the formation of hurricanes. Why is hurricane tracking important? Is it okay to be wrong?