It's Raining Fish and Spiders Read Free Page A

Tornado Fatalities
Texas
Mississippi
Alabama
    Highest Absolute Number of Tornado Occurrences
Texas
Oklahoma
Florida
    Highest Absolute Number of Killer Tornado Occurrences
Texas
Oklahoma
Arkansas
    Most Tornadoes in Any Month
    The record for the most tornadoes in any month (since modern tornado record keeping began in 1950) was set in April 2011 with 875 tornadoes. This easily broke the old mark of 543, set in May 2003.
    Most Tornadoes in Any Month Since 1950
1. April 2011
875
2. May 2003
543
3. June 1992
399
4. May 1995
391
5. June 1998
376
6. May 1991
335
7. May 1982
329
8. June 1990
329
9. June 1993
313
10. May 1998
310

    ----
    Ten Deadliest Single Tornadoes

    NOAA ONLY STARTED tracking tornado fatalities in 1950. Prior to 1950, information about tornado fatalities was gathered by an independent research group, The Tornado Project. Data in this table is drawn from both NOAA and The Tornado Project.

----
    Biggest Tornado Ever!
    The biggest known tornado is the Hallam, Nebraska, F4 tornado of May 22, 2004. Its peak width was nearly two and a half miles. This is probably close to the maximum size for tornadoes.

    Strongest Tornado Ever!
    We don’t know how fast winds can go inside a tornado. Tornado wind speeds have only been directly recorded in weaker storms, because strong and violent tornadoes destroy weather instruments. Mobile Doppler radars (which we will discuss later), such as the Oklahoma University “Doppler on Wheels,” have remotely sensed tornado wind speeds above ground level as high as about 302 mph (on May 3, 1999, near Bridge Creek, Oklahoma; that tornado caused F5 damage—this was before the introduction of the EF scale). These are the highest winds ever found on the Earth’s surface, even faster than hurricane winds. But ground-level wind speeds in the most violent tornadoes have never been directly measured.

    The Enhanced Fujita Damage Scale
    The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States, estimated by the damage they cause. The original “F” scale was invented in 1971 by University of Chicago physicist Theodore Fujita, the first and foremost tornado scientist.
    The new, enhanced Fujita (EF) scale went into operation on February 1, 2007. The scale was revised to reflect current, better examinations of tornado damage surveys, and to align wind speeds more closely with associated storm damage. The new scale takes into account more types of structures as well as vegetation, expands degrees of damage, and better accounts for variables such as the differences in construction of buildings and structures.
    The EF scale is not intended to assess wind speed as much as it is to derive what the wind speeds were in a particular tornado as determined by the type of damage that was left behind by the storm. The new scale takes into account quality of construction and standardizes different kinds of structures. The wind speeds on the original scale were deemed too high by meteorologists and engineers, and engineering studies indicated that slower winds than initially estimated caused the respective degrees of damage.
    The following graphic shows the damage assessment from the Enhanced Fujita Scale and what the corresponding tornado might look like. Images are courtesy of the National Severe Storms Lab.

    National Oceanic and Atmospheric Administration/Department of Commerce

    National Oceanic and Atmospheric Administration/Department of Commerce

    National Oceanic and Atmospheric Administration/Department of Commerce
    What Is a Derecho?
    Thunderstorms not only destroy lives and property by spawning tornadoes, they contain another type of wind that can be just as destructive. A prolonged windstorm that produces straight-line winds rather than or in addition to a tornado is called a derecho . Derecho (pronounced deh-RAY-cho) is the Spanish word for “direct” or