NWC REU 2012
May 21 - July 31



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Investigating the Relationship of Multi-Radar Multi-Sensor Parameters to Tornado Intensity

Jonathan Labriola, Kiel Ortega, Darrel Kingfield, and Madison Miller


What is already known:

  • There is increasing interest to use the WSR-88D velocity fields to diagnose the strength of a tornado while it is occurring.
  • Past work was unable to determine tornado strength using single radar velocity fields.
  • Multi-radar, multi-sensor data and experimental azimuthal shear products have not been tested before.

What this study adds:

  • Maximum lifetime values for a storm's shear and related velocity parameters do not discern weak (EF0-1) and strong (EF2-5) tornadoes well.
  • Tornado ratings were not dependent on maximum and average population density within the tornado path.
  • Shear area calculations, with limitations and caveats, showed some promise in differentiating between weak and strong tornadoes.


Derived radar parameters were investigated to determine the correlation between radar products and tornado intensity. More than four–hundred tornadoes from eleven tornado outbreaks between 2008 and 2011 were analyzed using WSR–88D radar sites. Radar reflectivity data was quality controlled, Doppler velocity data was dealiased and then merged in order to fill in any potential data gaps related to volume coverage geometry or blockages. Derived parameters included reflectivity values at certain heights and maximum azimuthal shear values within certain layers of the atmosphere. The lifetime maximum values of these fields surrounding tornado tracks were extracted and compared to the reported tornado intensities. It was found that lifetime maximums of radar derived parameters showed little discrimination of tornado intensity. However calculations of azimuthal shear area of the tornado paths did show some discrimination.

Full Paper [PDF]