1. Chapter 20: Severe Storms
Tornadoes
Hurricanes

2. Hurricanes!!

3. 2010 - 2015 Atlantic Hurricane Names
2011
2012
2013
2014
2015
Alex
Arlene
Alberto
Andrea
Arthur
Ana
Bonnie
Bret
Beryl
Barry
Bertha
Bill
Colin
Cindy
Chris
Chantal
Christobal
Claudette
Danielle
Don
Debby
Dorian
Dolly
Danny
Earl
Emily
Ernesto
Erin
Edouard
Erika
Fiona
Franklin
Florence
Fernand
Fay
Fred
Gaston
Gert
Gordon
Gabrielle
Gonzalo
Grace
Hermine
Harvey
Helene
Humberto
Hanna
Henri
Igor
Irene
Isaac
Ingrid
Isaias
Ida
Julia
Jose
Joyce
Jerry
Josephine
Joaquin
Karl
Katia
Kirk
Karen
Kyle
Kate
Lisa
Lee
Leslie
Lorenzo
Laura
Larry
Matthew
Maria
Michael
Melissa
Marco
Mindy
Nicole
Nate
Nadine
Nestor
Nana
Nicholas
Otto
Ophelia
Oscar
Olga
Omar
Odette
Paula
Philippe
Patty
Pablo
Paulette
Peter
Richard
Rina
Rafael
Rebekah
Rene
Rose
Shary
Sean
Sandy
Sebastien
Sally
Sam
Tomas
Tammy
Tony
Tanya
Teddy
Teresa
Virginie
Vince
Valerie
Van
Vicky
Victor
Walter
Whitney
William
Wendy
Wilfred
Wanda

5. At the surface, circulation is inward with a strong cyclonic (counterclockwise) flow, much like a giant whirlpool. In such warm core cyclones, upward flow is strongest along the eye wall and the eye itself is an area of sinking air. In the upper atmosphere, rising air flows outward.

8. Hurricane Structure
                                                                                                                                                                                                                                                

9. Eyewall

11. Hurricane Formation

13. Tornado
Violent windstorms that take the form of a rotating column of air called a vortex.
The vortex extends downward from a cumulonimbus cloud.

14. Tornado

16. Tornado Safety
DURING A TORNADO: Go to a basement. If you do not have a basement, go to an interior room without windows on the lowest floor such as a bathroom or closet. If you can, get under a sturdy piece of furniture, like a table. If you live in a mobile home get out. They offer little protection against tornadoes. Get out of automobiles. Do not try to outrun a tornado in your car, leave it immediately. If you’re outside, go to a ditch or low lying area and lie flat in it. Stay away from fallen power lines and stay out of damaged areas.

17. Light damage: Branches broken off trees; minor roof damage
 Fujita Scale of Tornado Intensity             
SCALE
WIND SPEED
POSSIBLE DAMAGE F0
 40-72 mph
Light damage: Branches broken off trees; minor roof damage F1
mph
Moderate damage: Trees snapped; mobile home pushed off foundations; roofs damaged F2
mph
Considerable damage: Mobile homes demolished; trees uprooted; strong built homes unroofed F3
mph
Severe damage: Trains overturned; cars lifted off the ground; strong built homes have outside walls blown away F4
mph
Devastating damage: Houses leveled leaving piles of debris; cars thrown 300 yards or more in the air F5
mph
Incredible damage: Strongly built homes completely blown away; automobile-sized missiles generated

18. Know the Lingo…
TORNADO WATCH - Tornadoes are possible in your area. Stay tuned to the radio or television news. TORNADO WARNING - A tornado is either on the ground or has been detected by Doppler radar. Seek shelter immediately!

19. When are tornadoes most likely to occur?
Tornadoes can happen at any time of the year and at any time of the day.
Peak times for tornadoes in the northern states are during the summer.
Tornadoes are most likely to occur between 3 p.m. and 9 p.m.

25. HURRICANES AND TORNADOES
What's the difference?
Hurricanes and tornadoes both form in warm, damp air when winds blow into each other from opposite directions. Hurricanes develop over warm, tropical oceans, while tornadoes form over land and are more violent. In a hurricane, the winds swirl around in a spiral at up to 200 mph. In the middle is a calm "eye" miles wide, surrounded by the worst wind and driving rain.
A tornado is a tall, funnel-shaped whirlwind of cloud up to 2,000 feet high. In the middle is an eye of descending air, surrounded by a strong upward current that sucks up or destroys everything in its path. Tornadoes can travel hundreds of miles before they die down.

26. How Do Hurricanes Get Their Names?
Hurricanes have been given names since the early 1900s, when an Australian weatherman would give names to the storms he tracked to help keep them apart. He enjoyed naming them after politicians he didn't like, so that he could then talk about the destruction that they caused. When the US Army got heavily into weather forecasting during World War II, workers there would start to nickname the storm systems after their wives or girlfriends, to give them their 15 minutes of fame. Soon they began to start with A and move through the letters, to make tracking the systems easier. By 1953 this was standard for the US Weather Bureau. In 1970 the National Weather Service had this responsibility, and moved to include men's names as well. Names are chosen for 6 years in a row, and then cycle around to the first set of names again. If a storm is truly memorable, that name is retired and a new one chosen to take its place.

27. Myth or Misconception #1 .... Tornadoes never strike big cities.
Myth or Misconception # Opening windows to equalize air pressure will save a roof, or even a home, from destruction by a tornado.
Myth or Misconception # Highway overpasses are a safe place to shelter if you are on the road when you see a tornado coming.