Tornado !

1. Tornado! “The most forceful and the most destructive of the storms”

2. WHAT IS A TORNADO?(The word TORNADO is from the Spanish words, "TRONADO" meaning thunderstorm and “TORNAR" meaning to turn.)A tornado is a violently rotating column of air that is in contact with the ground. It has been known to spin faster than 300 m.p.h. !

3. How do Tornadoes Form? • When all the conditions of a thunderstorm are present, humid air will rise high into the sky and cool and condense into towering clouds (Cumulonimbus), forming thunderstorms. This air rising into a thunderstorm is called an updraft. Tornadoes form in within a thunderstorm's updraft. • A change in wind direction and an increase in wind speed occurs during the updraft. • An invisible, horizontal spinning effect is created and tilts the rotating air from horizontal to vertical. • The strongest tornadoes are often near the edge of the updraft, not far from where air is descending in a downdraft caused by the thunderstorms with falling rain or hail. This is why a burst of heavy rain or hail sometimes announces a tornado's arrival. • A supercell (a large thunderstorm with a significant amount of updraft) is the type of storm most likely to produce tornadoes.

4. Clues to Tornado Formation • Strong rotation in the cloud base. • Whirling dust or debris on the ground under a cloud base - tornadoes sometimes have no funnel! • Hail or heavy rain followed by either dead calm or a fast, intense wind shift. • Many tornadoes are wrapped in heavy precipitation and can't be seen. • Day or night - Loud, continuous roar or rumble, which doesn't fade in a few seconds like thunder. • Night - Small, bright, blue-green to white flashes at ground level near a thunderstorm (as opposed to silvery lightning up in the clouds). These mean power lines are being snapped by very strong wind, maybe a tornado. • Night - Persistent lowering from the cloud base, illuminated or silhouetted by lightning

5. Watch vs. Warning • A tornado watch is issued when conditions are favorable for a tornado to form. • A tornado warning is issued when a tornado has been spotted! Go to an interior room (without windows) and duck/cover!

6. How are Tornados Classified? THE FUJITA SCALE • The Fujita Scale, (also known as the Fujita Pearson Scale) rates the amount of destruction a tornado causes to buildings and other structures after the tornado has passed. It also measures the path width and the path length of a tornado. • The Fujita Scale rates tornadoes from F0 to F6. If a tornado doesn't cause any structural damage or very little, it's an F0. the more damage, the higher the F number.

7. The Fujita Scale of Tornado Damage F-0: (Light Damage) Chimneys are damaged, tree branches are broken, shallow-rooted trees

8. F-1: (Moderate Damage) Roof surfaces are peeled off, windows are broken, some tree trunks are snapped, unanchored manufactured homes are over-turned, attached garages may be destroyed.

9. F-2: (Considerable Damage) Roof structures are damaged, manufactured homes are destroyed, debris becomes airborne (missiles are generated), large trees are snapped or uprooted.

10. F-3: (Severe Damage) Roofs and some walls are torn from structures, some small buildings are destroyed, non-reinforced masonry buildings are destroyed, most trees in forest are uprooted.

11. F-4: (Devastating Damage) Well-constructed houses are destroyed, some structures are lifted from foundations and blown some distance, cars are blown some distance, large debris becomes airborne.

12. F-5: (Incredible Damage) Strong frame houses are lifted from foundations, reinforced concrete structures are damaged, automobile-sized debris be-comes airborne, trees are completely debarked.

13. F-6 Inconceivable!!!!!!!!!!!!!!

14. TORNADO ALLEY...where tornadoes hit most in the world….The nation's heartland –a 10-state area stretching from Texas to North Dakota that also includes Colorado, Iowa, Illinois, Indiana, Ohio, Missouri and Arkansas

17. Why here? Why in these states? A mass of moist warm air (mT) that comes from the southeast (Gulf of Mexico) and a mass of cool dry air (cP) that comes from the northwest meet in this area producing violent weather and tornadoes.

18. Did you know????? *Although tornadoes form all over the world, The United States gets hit more frequently and stronger. *The states that have the mostkiller tornadoes are ranked: 1. Texas 2. Oklahoma 3. Arkansas *Usually, tornadoes form between 3 and 7 PM.

19. *When a funnel forms over water, it's called a waterspout. When it forms over the desert, it's called a dustdevil. Neither are as strong as tornadoes. *The average forward speed of a tornado is 30 to 40 m.p.h., but can go as fast as 70 m.p.h. And has rotational speed that can be more than 300 MPH !! *Tornadoes can occur in series (one after another) and more than one can form from the same cloud System !The worst series in history was on March 18,1925. 689 were killed in Missouri, Illinois, and Indiana *Tornadoes can be invisible !!! *Even though winds are usually deflected to the RIGHT or Clockwise in the Northern Hemisphere (opposite in the S. H.), tornadoes can take on any spin direction!!! *

20. *Tornadoes can be over a mile wideor really skinny ! *Tornadoes occur mostly in May.January and February are the months tornadoes occur least.

21. Safety • Seek shelter in a sturdy, well-constructed building. • Protect your head. • Get away from windows. • Basements and cellars are ideal. If none the bathtub is next best! • Do not try to outrun/outdrive a tornado. If you cannot seek shelter in a building, lie flat in a ditch or ravine and clasp your hands behind your head to protect yourself from flying debris. • http://www.spc.noaa.gov/faq/tornado/safety.html