Chapter 20.3 HURRICANES!
Hurricanes
• Whirling tropical cyclones that produce winds of at least 119 km/hr.
Occurrence of Hurricanes
• Most form between 5 and 20 degrees N and S latitude. • The North Pacific has the greatest number of storms (avg 20/yr)
Hurricane Katrina
Development of Hurricanes
They develop most often in the late summer when water temperatures are warm enough to provide the necessary heat and moisture to the air.
Hurricane Anatomy
• Eye – zone of scattered clouds – Calm – averaging about 20 kilometers in diameter at the center of a hurricane. • Eye Wall – doughnut-shaped area of intense cumulonimbus development – very strong winds (surrounds the eye of a hurricane)
Anatomy of a Hurricane
Satellite view from above.
Basic Stages Tropical Depression
The Formation of a Hurricane
Winds near the center are constantly between 23 - 39 mph
Tropical Storm Winds between 39-73 mph Hurricane Winds at 74 mph
The Steps in Hurricane Formation
1. Warm air above the water rises and cools to form clouds.
2. More warm air comes in from all sides to replace the air that was rising. (This inward wind rotates because of the Coriolis Effect… this is why hurricanes look like pin-wheels) 3. Hurricanes use energy from the warm ocean water to grow stronger. As long as it has warm water a hurricane will continue to grow.
Hurricane Intensity
• The intensity of a hurricane is described using the Saffir-Simpson Scale.
• Storm surge - abnormal rise of the sea along a shore as a result of strong winds
Different Terms for a Hurricane
• Hurricanes are called by different names in the
different regions of the world
–In the Atlantic or Eastern Pacific Ocean • They are called..."hurricanes"
– Western North Pacific and Philippines • called "typhoons“
– Indian and South Pacific Ocean •They are called… "cyclones"
How Hurricanes are Named
Hurricane History…
• Short distinctive names are quicker and less subject to error than using latitude-longitude • These advantages are especially important in exchanging detailed storm information between hundreds of widely scattered stations, coastal bases, and ships at sea.
• Since 1953, storms in the Atlantic have been named from lists originated by the National Hurricane Center. They are now maintained and updated by an international committee of the World Meteorological Organization.
How Hurricanes are Named
• The original name lists featured only women's names. • In 1979, men's names were introduced and they alternate with the women's names.
• The WMO uses six lists in rotation and the same lists are reused every six years. The only time a new name is added is if a hurricane is very deadly or costly. Then the name is retired and a new name is chosen. The 2005 list will be used again in 2011.
Retired Names
Retired Name
Allison Floyd Georges
Replacement Name
Andrea Franklin Gaston
Iris Keith Lenny Michelle
Ingrid Kirk Lee Melissa
1994
1995
1996
1997
1998
1999
Alberto Storm Beryl Names Chris for 1994Debby 1999 Ernesto
Florence Gordon
Allison Barry
Chantal
Arthur Bertha
Cesar
Ana Bill
Claudette
Alex Bonnie
Charley
Arlene Bret
Cindy
Dean Erin
Felix Gabielle
Dolly Edouard
Fran Gustav
Danny Erika
Fabian Grace
Danielle Earl
Frances Georges
Dennis Emily
Floyd Gert
Helene
Isaac Joyce
Humberto
Iris Jerry
Hortense
Isidore Josephine
Henri
Isabel Juan
Hermine
Ivan Jeanne
Harvey
Irene Jose
Keith
Leslie Michael
Karen
Luis Marilyn
Kyle
Lili Marco
Kate
Larry Mindy
Karl
Lisa Mitch
Katrina
Lenny Maria
Nadine
Oscar Patty Rafael Sandy Tony Valerie William
Noel
Opal Pablo Roxanne Sebastien Tanya Van Wendy
Nana
Omar Paloma Rene Sally Teddy Vicky Wilfred
Nicholas
Odette Peter Rose Sam Teresa Victor Wanda
Nicole
Otto Paula Richard Shary Tomas Virginie Walter
Nate
Ophelia Philippe Rita Stan Tammy Vince Wilma
Atlantic Names
2005 Arlene Bret Cindy Dennis Emily Franklin Gert Harvey Irene Jose Katrina Lee Maria Nate Ophelia Philippe Rita Stan Tammy Vince Wilma 2006 Alberto Beryl Chris Debby Ernesto Florence Gordon Helene Isaac Joyce Kirk Leslie Michael Nadine Oscar Patty Rafael Sandy Tony Valerie William 2007 Andrea Barry Chantal Dean Erin Felix Gabrielle Humberto Ingrid Jerry Karen Lorenzo Melissa Noel Olga Pablo Rebekah Sebastien Tanya Van Wendy 2008 Arthur Bertha Cristobal Dolly Edouard Fay Gustav Hanna Ike Josephine Kyle Laura Marco Nana Omar Paloma Rene Sally Teddy Vicky Wilfred 2009 Ana Bill Claudette Danny Erika Fred Grace Henri Ida Joaquin Kate Larry Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda 2010 Alex Bonnie Colin Danielle Earl Fiona Gaston Hermine Igor Julia Karl Lisa Matthew Nicole Otto Paula Richard Shary Tomas Virginie Walter
Hurricane Katrina
– It was the first Category 5 hurricane of the 2005 Atlantic Hurricane Season
– It was the sixth-strongest Atlantic Hurricane ever recorded. – The storm weakened to a Category 3 when it made landfall along the Central Gulf Coast on August 29, 2005 – The storm surge from Katrina caused catastrophic damage along the coastlines
– Leeves in New Orleans were breached by the surge, ultimately flooding about 80% of the city. – Wind damage was reported well inland, impeding relief efforts. – Katrina is estimated to be responsible for $75 billion in damages, making it the costliest hurricane in United States history – The storm has killed 1,417 people, becoming the deadliest U.S. hurricane since the 1928 Okeechobee Hurricane.
The Path of Hurricane Katrina
ETUDE