How Hurricanes Form Begins over warm water as a low-pressure area, or tropical disturbance If it grows in size and strength it becomes a Tropical Storm –Continued growth and it becomes a Hurricane.
Hurricanes A tropical storm that has winds of 119km/h or higher Typically 600km in diameter Usually last a week or longer Hurricane season lasts June 1 – Nov 30 Cyclone –Indian Ocean: Cyclone Typhoon –Western Pacific: Typhoon.
How Hurricanes Form warm, humid airA hurricane gets energy from warm, humid air at the ocean surface forms cloudsAs the air rises, and forms clouds, more air is drawn in Low PressureWinds spiral inward towards the area of Low Pressure.
How Hurricanes Form Inside the storm: –Bands of heavy rain –high winds up to 320km/h –The lowest air pressure –Warmest temperature. The lower the pressure –The stronger the winds blowing towards the center.
Exit Pass energyfuels lose strength dissipate What gives energy to / fuels a hurricane? What causes a hurricane to lose strength and dissipate?
Hurricanes travel in the direction of the global winds Trade Winds –In the Atlantic Ocean are steered by the Trade Winds to the East moist air from the ocean is cut off Once it passes over land, the warm, moist air from the ocean is cut off –The hurricane slows down –Loses strength –Leaves heavy rainfall behind –Leaves heavy rainfall behind. How Hurricanes Move
Eye the hurricane’s center A ring of clouds surrounding a quiet “Eye,” the hurricane’s center Winds get stronger as the eye approaches and “reverse” when it passes by Eye Weather in the Eye –Calm –Clear sky –Clear sky. The Eye of the Hurricane
Storm Surge A “dome” or wave of water that comes on shore with the hurricane high winds low pressureFormed by the high winds (push the water) and the low pressure (water level rises) –Up to 6m (20ft) above sea level.
Hurricane Damage Hurricanes uproot trees, smash buildings, and destroy power lines Heavy rains flood roads. Category Wind Speed (mph) Wind Speed (kmh) Damage at Landfall Storm Surge (feet) 174-95119-153Minimal4-5 296-110154-177Moderate6-8 3111-130178-209Extensive9-12 4131-155210-250Extreme13-18 5Over 155251+Catastrophic19+
Hurricane Safety Hurricane Watch means conditions are possible with in the next 36 hours –Evacuate or move away temporarily A hurricane warning means conditions are expected within 24 hours –Leave immediately!
Hurricane Safety Advances in communications and satellites have made tracking hurricanes easier, and therefore less deadly Stay near interior of building, away from windows Plan for flooding.