TornadoTouchdown : public <<Feature>> class
Created: 9/25/2007 12:26:45 PM
Modified: 9/25/2007 12:38:49 PM
Project:
Advanced:
<p>This map layer shows tornado touchdown points in the United States, Puerto Rico, and the U.S. Virgin Islands, from 1950 to 2004.  Statistical data were obtained from the National Weather Service, Storm Prediction Center (SPC).  The SPC data originate from the Severe Thunderstorm Database and the National Oceanic and Atmospheric Administration (NOAA) Storm Data publication.<br/></p><p><br/></p><p>These data are intended for geographic display and analysis at the<br/></p><p>national level, and for large regional areas.  The data should be<br/></p><p>displayed and analyzed at scales appropriate for 1:2,000,000-scale data.<br/></p><p>No responsibility is assumed by the National Weather Service or the<br/></p><p>National Atlas of the United States in the use of these data.<br/></p><p><br/></p><p>This map layer represents an edited version of the information available,<br/></p><p>in ASCII format, from the SPC page at <http://www.spc.noaa.gov/wcm/>.  <br/></p><p>The SPC data set contains additional attributes, more information on tornadoes that affected multiple States, and additional tornadoes that were deleted from this map layer due to attribution problems.<br/></p><p><br/></p><p>Historical tornado data is also available in the SPC's Historical Tornado<br/></p><p>Data Archive <http://www.spc.noaa.gov/archive/tornadoes/index.html>.<br/></p><p><br/></p><p>For more information on the Fujita Tornado Damage Scale, see<br/></p><p><http://www.spc.noaa.gov/faq/tornado/f-scale.html> and<br/></p><p><http://www.spc.noaa.gov/wcm/The%20Fujita%20Scale_files/frame.htm>.<br/></p><p><br/></p><p>For information on current tornado watches and advisories, see<br/></p><p><http://www.spc.noaa.gov/products/wwa/>.<br/></p><p><br/></p><p>General information on tornadoes is available from the NOAA SPC's Online<br/></p><p>Tornado FAQ page at <http://www.spc.noaa.gov/faq/tornado/>, <br/></p><p>and from<br/></p><p>NOAA's tornado page at <http://www.noaa.gov/tornadoes.html>.<br/></p>
Attribute Details
public Quantity
  TornadoTouchdownNumTornadosInStateQuantity
Range:0 to 1
Notes: The number of the tornado in the State, for a given year.<br />Definition Source:  National Oceanic and Atmospheric Administration, Storm Prediction Center
public Quantity
  TornadoTouchdownNumTornadosInYearQuantity
Range:0 to 1
Notes: A count of tornadoes during the year.  If a tornado with evidence of damage lifts off and touches down again within two miles, it is considered the same tornado.
public Quantity
  TornadoTouchdownNumStatesTraversedQuantity
Range:0 to 1
Notes: The number of States traversed by the tornado.  Note that this is not a count of tornadoes, it is a count of the records, in the source data base, associated with one tornado.
public Text
  TornadoTouchdownMultiStateTornadoText
Range:0 to 1
Notes: An indication of whether the record describes a tornado that affected<br />several States or only a single State.
public Number
  TornadoTouchdownTouchDownLat
Range:0 to 1
Notes: The latitude of the point where the tornado touched down.
public Number
  TornadoTouchdownTouchDownLon
Range:0 to 1
Notes: The longitude of the point where the tornado touched down.
public Number
  TornadoTouchdownLiftOffLat
Range:0 to 1
Notes: The latitude of the point where the tornado lifted off.
public Number
  TornadoTouchdownLiftOffLon
Range:0 to 1
Notes: The West longitude of the point where the tornado lifted off.
public LengthMeasure
  TornadoTouchdownStormTrackLengthMeasure
Range:0 to 1
Notes: The length of the tornado track in tenths of a statute mile (146 = 14.6<br />miles).   Tracks may be nonlinear, so the length may not be the same as the great-circle distance from the touchdown point to the lift-off<br />point. Definition Source: National Oceanic and Atmospheric Administration, Storm Prediction Center<br />
public LengthMeasure
  TornadoTouchdownWidthMeasure
Range:0 to 1
Notes: For tornadoes prior to 1994, the mean tornado path width in tens of feet<br />(528.00 = 5280.0 feet or 1 mile.)  This is the mean width along the<br />entire track.  The minimum width is assumed to be 30 feet.  A width was<br />computed for each State that a tornado affected, and the mean was<br />calculated from those values.<br />For tornadoes from 1994 and later, the maximum width in tens of feet.<br />Definition Source: National Atlas of the United States<br />
public Number
  TornadoTouchdownFujitaScaleNumeric
Range:0 to 1
Notes: The damage classification according to the Fujita Tornado Damage Scale.<br />The categories are based upon the estimated maximum winds occurring<br />within the funnel.  Wind estimates associated with damage are crude at<br />best.  Only one classification is given for each tornado. See<br /><http://www.spc.noaa.gov/faq/tornado/f-scale.html> and<br /><http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/educational/fujita.html><br />for detailed information on the Fujita Tornado Scale.<br />Definition Source:  National Oceanic and Atmospheric Administration, Storm Prediction Center<br /><br />Definition Source:  National Atlas of the United States
public USStateCode
  TornadoTouchdownStateAlphaCode
Range:0 to 1
Notes: Alpha code for touchdown State.
public USStateNumericCode
  TornadoTouchdownStateNumericCode
Range:0 to 1
Notes: FIPS numeric code for touchdown State.
public USCountyCode
  TornadoTouchdownCountyFIPSCode
Range:0 to *
Notes: Alpha code for traversed county.
public String
  TornadoTouchdownSNCode
Range:0 to 1
Notes: SN<br />Source: HSIP v3 2008
public String
  TornadoTouchdownSGCode
Range:0 to 1
Notes: SG<br />Source: HSIP v3 2008
Object Type Connection Notes
«Feature» Hazard Class Generalization  
«Feature» HistoricalTornadoTrack Class Generalization