TEMPORAL AND SPATIAL VARIATION ANALYSIS OF TORNADO TOUCHDOWNS

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TEMPORAL AND SPATIAL VARIATION ANALYSIS OF
TORNADO TOUCHDOWNS

• Environmental Applications of GIS
• GEOG5650

Nitin Katiyar
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Introduction

• What is a Tornado According to the Glossary of
  Meteorology (AMS 2000), a tornado is "a violently
  rotating column of air, pendant from a cumuliform
  cloud or underneath a cumuliform cloud, and often
  (but not always) visible as a funnel cloud."
• How do tornado form Classic answer Worm moist
  Gulf air meets cold Canadian air and dry air from
  the Rockies

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Tornadoes Affected Regions
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Tornadoes Common Areas (TCA)

• 20 States Selected

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Tornadoes in USA for 1961 - 1990
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Tornadoes in TCA for 1961-1990

• Area 40.8
• Tornadoes 75.6

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Tornadoes in Tennessee for 1961-1990

• Area 1.3
• Tornadoes 1.5

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Trend of Tornado Occurrence
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Temporal variation of Tornadoes in TCA
(21 Jun 22 Sep)
(21 Mar 20 Jun)
(23 Sep 20 Dec)
(21 Dec 20 Mar)
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Temporal variation of Tornadoes in Tennessee
(21 Mar 20 Jun)
(21 Jun 22 Sep)
(21 Dec 20 Mar)
(23 Sep 20 Dec)
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Seasonal Distribution of Tornadoes
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Conclusion

• Tornadoes more concentrated on the Southeastern
  and Central part of US. 20 States covering only
  40 of the total area gets 75 of the tornadoes.
• In Tennessee Western and Central part gets more
  tornadoes than Eastern parts.
• Overall trend shows that number of tornadoes
  increasing over the years.
• In contrary to the trend in whole US. TCA gets
  more tornadoes in Spring than rest of the year.
• Tennessee gets about 2/3 of the total tornadoes
  in Spring.

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References

• Tornado data http//gis.unc.edu/data/
• Tornado Alley http//www.windows.ucar.edu/earth/im
  ages/tornado_alley.jpg
• Tornado Tracks Information
• http//www.lib.unc.edu/reference/gis/datafinder/in
  dex.html?individual_datalayer_details1data_layer
  _id103
• http//www.ncdc.noaa.gov/oa/about/cdrom/climatls2/
  datadoc.htmlTORN47

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Thank You