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Learn how hurricanes form in the atmosphere, become destructive storms, and are tracked by experts. Explore the Coriolis Effect, energy patterns, potential hazards, and preparation tips. Discover the classification system and historical hurricanes like Katrina.
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What needs to happen in the atmosphere for storms to form? • Warm, moist air rises in the troposphere • Warm air condenses and releases heat in the atmosphere
Tropical Storms • Tropical storms are large, rotating, low pressure storms • The strongest of these storms are known as hurricanes
Tropical Storms • Tropical storms form in a low pressure system when water evaporates off of warm, tropical waters • This creates a region of low pressure which attracts surrounding air • They spin and move across Earth’s surface
So Why Do They Spin? • Coriolis Effect! https://www.youtube.com/watch?v=i2mec3vgeaI
How do hurricanes become hurricanes? • As the rotation (caused by the Coriolis Effect) of the storm increases, the winds around the center pick up speed until they become first a tropical storm (sustained winds of 35 mph), and then a hurricane (sustained winds of 75 mph, or greater).
The highest winds are found in the eyewall of a hurricane. • Damaging winds and heavy rain can also occur in the rainbands of a hurricane. • Air in a rotating hurricane is drawn into the center of the storm, called the eye. • When the air reaches the eye, it rises up through the eyewall and spreads out on top of the hurricane forming dense cirrus clouds. • Inside the eye is relatively calm and 20-40 miles long
Energy of a Hurricane • Hurricanes will last until it can no longer produce enough energy to sustain itself • Usually happens when a hurricane moves over land – act as brakes to the rotation of the storm
Hurricane Damage • The most extreme forms of damage from a hurricane are along coastlines. • Here, only a single home remains standing along the Texas coastline after Hurricane Ike hit in 2008. • Hurricane damage along a coastline is the most severe because of high winds, pounding rain, and the storm surge. • What is a storm surge?
Hazards – Storm surge • Occurs when hurricane force winds drive a mound of ocean water toward coastal areas • Can reach 6 meters above normal sea level • 95% of the storm surge height is caused by wind pushing the ocean in front of the storm.
Hurricane Tracking How strong will they get? Where will they go?
How is a hurricane tracked? National Hurricane Center • Weather satellites collect photos and other data each day during hurricane season. • Images from several different types of satellites are studied to estimate the position, direction, and intensity of a storm. • Then, hurricane tracking aircraft fly into the storm to confirm wind speed and direction, rainfall, and internal pressure of the hurricane eye.
Classifying Hurricanes • The Saffir-Simpson hurricane scale classifies hurricanes based on: • Wind speed • Air pressure • Potential for property damage
Hurricane Preparation • Hurricanes can be observed from weather satellites orbiting the Earth • Can improve hurricane warnings which can give people time to leave • During hurricanes you should: • Board up the house • Stay indoors • Have plenty of food and water • Stay away from windows
Before and after photographs for the damage along the New Jersey coastline during Hurricane Sandy in 2012.
Hurricane Katrina • New Orleans, Louisiana. Category 3 Hurricane • 1,836 Deaths, mostly resulted from the levee breaking • Deadliest US Hurricane since 1928