In Situ, Doppler Radar, and Video Observations of the Interior Structure of a Tornado and the Wind–Damage Relationship

Joshua Wurman Center for Severe Weather Research, Boulder, Colorado

Search for other papers by Joshua Wurman in
Current site
Google Scholar
PubMed
Close
,
Karen Kosiba Center for Severe Weather Research, Boulder, Colorado

Search for other papers by Karen Kosiba in
Current site
Google Scholar
PubMed
Close
, and
Paul Robinson Center for Severe Weather Research, Boulder, Colorado

Search for other papers by Paul Robinson in
Current site
Google Scholar
PubMed
Close
Restricted access

Direct observations of the winds inside a tornado were obtained with an instrumented armored vehicle, the Tornado Intercept Vehicle (TIV), and integrated with finescale mobile Doppler radar (Doppler on Wheels) data revealing, for the first time, the structure of the near-ground three-dimensional wind field in and around the core region of a strong tornado, and permitting comparison with conceptual models. Inward and upward spiraling near-surface flow, upward motion near the surface, and an axial downdraft aloft are documented, as well as a periodic oscillation in tornado intensity. Simultaneous video documentation of damage occurring during the tornado is related to the direct wind observations, permitting the first comparisons of the time history of damage to the time history of directly measured winds and a limited evaluation of the underlying assumptions and quantitative relationships in the enhanced Fujita (EF) scale.

CORRESPONDING AUTHOR: Joshua Wurman, Center for Severe Weather Research, 1945 Vassar Circle, Boulder, CO 80305, E-mail: jwurman@cswr.org

Direct observations of the winds inside a tornado were obtained with an instrumented armored vehicle, the Tornado Intercept Vehicle (TIV), and integrated with finescale mobile Doppler radar (Doppler on Wheels) data revealing, for the first time, the structure of the near-ground three-dimensional wind field in and around the core region of a strong tornado, and permitting comparison with conceptual models. Inward and upward spiraling near-surface flow, upward motion near the surface, and an axial downdraft aloft are documented, as well as a periodic oscillation in tornado intensity. Simultaneous video documentation of damage occurring during the tornado is related to the direct wind observations, permitting the first comparisons of the time history of damage to the time history of directly measured winds and a limited evaluation of the underlying assumptions and quantitative relationships in the enhanced Fujita (EF) scale.

CORRESPONDING AUTHOR: Joshua Wurman, Center for Severe Weather Research, 1945 Vassar Circle, Boulder, CO 80305, E-mail: jwurman@cswr.org
Save
  • Alexander, C. R., and J. Wurman, 2008: Updated mobile radar climatology of supercell tornado structures and dynamics. Extended Abstracts, 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 19.4. [Available online at https://ams.confex.com/ams/pdfpapers/141821.pdf.]

    • Search Google Scholar
    • Export Citation
  • Atkins, N. A., R. McGee, R. Ducharme, R. M. Wakimoto, and J. Wurman, 2012: The LaGrange tornado during VORTEX 2. Part II: Photogrammetric analysis of the tornado combined with dual-Doppler radar data. Mon. Wea. Rev., 140, 29392958.

    • Search Google Scholar
    • Export Citation
  • Barnes, S. L., 1964: A technique for maximizing details in numerical weather-map analysis. J. Appl. Meteor., 3, 396409.

  • Bluestein, H. B., W.-C. Lee, M. Bell, C. C. Weiss, and A. L. Pazmany, 2003: Mobile Doppler radar observations of a tornado in a supercell near Bassett, Nebraska, on 5 June 1999. Part II: Tornado-vortex structure. Mon. Wea. Rev., 131, 29682984.

    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., C. C. Weiss, and A. L. Pazmany, 2004: The vertical structure of a tornado near Happy, Texas, on 5 May 2002: High-resolution, W-band, Doppler radar observations. Mon. Wea. Rev., 132, 23252337.

    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., C. C. Weiss, M. M. French, E. M. Holthaus, R. L. Tanamachi, S. Frasier, and A. L. Pazmany, 2007: The structure of tornadoes near Attica, Kansas, on 12 May 2004: High-resolution, mobile, Doppler radar observations. Mon. Wea. Rev., 135, 475506.

    • Search Google Scholar
    • Export Citation
  • Burgers, J. M., 1948: A mathematical model illustrating the theory of turbulence. Adv. Appl. Mech., 1, 171199.

  • Church, C. R., and J. T. Snow, 1993: Laboratory models of tornadoes. The Tornado: Its Structure, Dynamics, Prediction, and Hazards, Geophys. Monogr., Vol. 79, Amer. Geophys. Union, 277295.

    • Search Google Scholar
    • Export Citation
  • Church, C. R., J. T. Snow, G. L. Baker, and E. M. Agee, 1979: Characteristics of tornado-like vortices as a function of swirl ratio: A laboratory investigation. J. Atmos. Sci., 36, 17551776.

    • Search Google Scholar
    • Export Citation
  • Davies-Jones, R. P., 1986: Tornado dynamics. Thunderstorm Morphology and Dynamics, Vol. 2, Thunderstorms—A Social, Scientific, and Technological Documentary, 2nd ed., E. Kessler, Ed., University of Oklahoma Press, 197236.

    • Search Google Scholar
    • Export Citation
  • Doswell, C. A., III, H. E. Brooks, and N. Dotzek, 2009: On the implementation of the enhanced Fujita scale in the USA. Atmos. Res., 93, 554563.

    • Search Google Scholar
    • Export Citation
  • Dowell, D. C., C. R. Alexander, J. M. Wurman, and L. J. Wicker, 2005: Centrifuging of hydrometeors and debris in tornadoes: Radar-reflectivity patterns and wind-measurement errors. Mon. Wea. Rev., 123, 15011524.

    • Search Google Scholar
    • Export Citation
  • Edwards, R., J. G. LaDue, J. T. Ferree, K. Scharfenberg, C. Maier, and W. L. Coulbourne, 2013: Tornado intensity estimation: Past, present, and future. Bull. Amer. Meteor. Soc., in press.

    • Search Google Scholar
    • Export Citation
  • FEMA, 2012: Mitigation Assessment Team Report– Spring 2011 tornadoes: April 25–28 and May 22—Building performance observations, recommendations, and technical guidance. FEMA P-908, 512 pp. [Available online at www.fema.gov/library/viewRecord.do?fromSearch=fromsearch&id=5633.]

    • Search Google Scholar
    • Export Citation
  • Fiedler, B. H., and R. Rotunno, 1986: A theory for the maximum windspeeds in tornado-like vortices. J. Atmos. Sci., 43, 23282340.

  • Fouts, J. L., D. L. James, and C. W. Letchford, 2003: Pressure distribution on a cubical model in tornado-like flow. Preprints, 11th Int. Conf. on Wind Engineering, Lubbock, TX, ICWE.

    • Search Google Scholar
    • Export Citation
  • Haan, F. L., Jr., V. K. Balaramudu, and P. P. Sarkar, 2010: Tornado-induced wind loads on a low-rise building. J. Struct. Eng., 136, 106116.

    • Search Google Scholar
    • Export Citation
  • Howells, P. A. C., R. Rotunno, and R. K. Smith, 1988: A comparative study of atmospheric and laboratoryanalogue numerical tornado-vortex models. Quart. J. Roy. Meteor. Soc., 114, 801822.

    • Search Google Scholar
    • Export Citation
  • Kosiba, K. A., and J. Wurman, 2010: The threedimensional axisymmetric wind field structure of the Spencer, South Dakota, 1998, tornado. J. Atmos. Sci., 67, 30743083.

    • Search Google Scholar
    • Export Citation
  • Kosiba, K. A., and J. Wurman, 2012: Near-ground radar and anemometer measurements in the Russell, Kansas (2005) tornado. Preprints, 26th Conf. on Severe Local Storms, Nashville, TN, Amer. Meteor. Soc., 16.4. [Available online at https://ams.confex.com/ams/26SLS/webprogram/Paper211752.html]

    • Search Google Scholar
    • Export Citation
  • Kosiba, K. A., R. J. Trapp, and J. Wurman, 2008: An analysis of the axisymmetric three-dimensional low level wind field in a tornado using mobile radar observations. Geophys. Res. Lett., 35, L05805, doi:10.1029/2007GL031851.

    • Search Google Scholar
    • Export Citation
  • Kosiba, K. A., J. Wurman, P. Markowski, Y. Richardson, P. Robinson, and J. Marquis, 2013: Genesis of the Goshen County, Wyoming, tornado on 5 June 2009 during VORTEX2. Mon. Wea. Rev., 141, 11571181.

    • Search Google Scholar
    • Export Citation
  • Kuai, L., F. L. Haan Jr., W. Gallus Jr., and P. P. Sarkar, 2008: CFD simulations of the flow field of a laboratorysimulated tornado for parameter sensitivity studies and comparison with field measurements. Wind Struct., 11, 7596.

    • Search Google Scholar
    • Export Citation
  • Lee, W.-C., and J. Wurman, 2005: The diagnosed structure of the Mulhall tornado. J. Atmos. Sci., 62, 23732393.

  • Lee, W.-C., B. J.-D. Jou, P.-L. Chang, and S.-M. Deng, 1999: Tropical cyclone kinematic structure retrieved from single-Doppler radar observations. Part I: Interpretation of Doppler velocity patterns and the GBVTD technique. Mon. Wea. Rev., 127, 24192439.

    • Search Google Scholar
    • Export Citation
  • Lewellen, D. C., and W. S. Lewellen, 2007a: Near-surface intensification of tornado vortices. J. Atmos. Sci., 64, 21762194.

  • Lewellen, D. C., and W. S. Lewellen, 2007b: Near-surface vortex intensification through corner flow collapse. J. Atmos. Sci., 64, 21952209.

    • Search Google Scholar
    • Export Citation
  • Lewellen, D. C., W. S. Lewellen, and J. Xia, 2000: The influence of a local swirl ratio on tornado intensification near the surface. J. Atmos. Sci., 57, 527544.

    • Search Google Scholar
    • Export Citation
  • Lewellen, D. C., B. Gong, and W. S. Lewellen, 2008: Effects of finescale debris on near-surface tornado dynamics. J. Atmos. Sci., 65, 32473262.

    • Search Google Scholar
    • Export Citation
  • Lewellen, W. S., 1976: Assessment of knowledge and implications for man. Proc. Symp. on Tornadoes, Lubbock, TX, Texas Tech University, 107143.

    • Search Google Scholar
    • Export Citation
  • Lewellen, W. S., D. C. Lewellen, and R. I. Sykes, 1997: Large-eddy simulation of a tornado's interaction with the surface. J. Atmos. Sci., 54, 581605.

    • Search Google Scholar
    • Export Citation
  • Lott, N., A. Smith, J. Crouch, T. Houston, and K. Shein, cited 2012: Billion dollar U.S. weather/climate disasters, 1980–2011. Fact sheet, NOAA/National Climatic Data Center. [Available online at www.ncdc.noaa.gov/oa/reports/billionz.html.]

    • Search Google Scholar
    • Export Citation
  • Markowski, P., and Coauthors, 2012a: The pretornadic phase of the Goshen County, Wyoming, supercell of 5 June 2009 intercepted by VORTEX2. Part I: Evolution of kinematic and surface thermodynamic fields. Mon. Wea. Rev., 140, 28872915.

    • Search Google Scholar
    • Export Citation
  • Markowski, P., and Coauthors, 2012b: The pretornadic phase of the Goshen County, Wyoming, supercell of 5 June 2009 intercepted by VORTEX2. Part II: Intensification of low-level rotation. Mon. Wea. Rev., 140, 29162938.

    • Search Google Scholar
    • Export Citation
  • Marquis, J. N., Y. P. Richardson, and J. M. Wurman, 2007: Kinematic observations of misocyclones along boundaries during IHOP. Mon. Wea. Rev., 135, 17491768.

    • Search Google Scholar
    • Export Citation
  • McDonald, J. R., G. S. Forbes, and T. P. Marshall, 2004: The enhanced Fujita (EF) scale. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., 7.

    • Search Google Scholar
    • Export Citation
  • Nolan, D. S., and M. T. Montgomery, 2002: Nonhydrostatic, three-dimensional perturbations to balanced, hurricane-like vortices. Part I: Linearized formulation, stability, and evolution. J. Atmos. Sci., 59, 29893020.

    • Search Google Scholar
    • Export Citation
  • Potter, S., 2007: Fine-tuning Fujita. Weatherwise , 60, 6471.

  • Rott, N., 1958: On the viscous core of a line vortex. Z. Angew Math. Mech., 9, 543553.

  • Rotunno, R., 1979: A study in tornado-like vortex dynamics. J. Atmos. Sci., 36, 140155.

  • Selvam, R. P., and P. C. Millett, 2003: Computer modeling of tornado forces on buildings. Wind Struct., 6, 209220.

  • Simiu, E., and R. H. Scanlan, 1996: Wind Effects on Structures: Fundamentals and Applications to Design. John Wiley and Sons, 688 pp.

  • Snow, J. T., 1982: A review of recent advances in tornado vortex dynamics. Rev. Geophys. Space Phys., 20, 953964.

  • Tanamachi, R. L., H. B. Bluestein, W.-C. Lee, M. Bell, and A. Pazmany, 2007: Ground-based velocity display (GBVTD) analysis of W-band Doppler radar data in a tornado near Stockton, Kansas, on 15 May 1999. Mon. Wea. Rev., 135, 783800.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., N. T. Atkins, and J. Wurman, 2011: The LaGrange tornado during VORTEX2. Part I: Photogrammetric analysis of the tornado combined with single-Doppler radar data. Mon. Wea. Rev., 139, 22332258.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., P. Stauffer, W.-C. Lee, N. T. Atkins, and J. Wurman, 2012: Finescale structure of the LaGrange, Wyoming, tornado during VORTEX2: GBVTD and photogrammetric analyses. Mon. Wea. Rev., 140, 33973418.

    • Search Google Scholar
    • Export Citation
  • Wind Science and Engineering Center, 2006: A recommendation for an Enhanced Fujita Scale (EF-Scale). Wind Science and Engineering Center, Texas Tech University, 111 pp. [Available online at www.depts.ttu.edu/weweb/Pubs/fscale/EFScale.pdf.]

    • Search Google Scholar
    • Export Citation
  • Wurman, J., 2001: The DOW mobile multiple Doppler network. Preprints, 30th Int. Conf. on Radar Meteorology, Munich, Germany, Amer. Meteor. Soc., 9597.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., 2002: The multiple-vortex structure of a tornado. Wea. Forecasting , 17, 473505.

  • Wurman, J., and J. Winslow, 1998: Intense sub-kilometer-scale boundary layer rolls in Hurricane Fran. Science , 280, 555557.

  • Wurman, J., and S. Gill, 2000: Finescale radar observations of the Dimmitt, Texas (2 June 1995), tornado. Mon. Wea. Rev., 128, 21352164.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., and T. Samaras, 2004: Comparison of in situ pressure and DOW Doppler winds in a tornado and RHI vertical slices through 4 tornadoes during 1996–2004. Extended Abstracts, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., 15.4. [Available online at https://ams.confex.com/ams/11aram22sls/techprogram/paper_82352.htm.]

    • Search Google Scholar
    • Export Citation
  • Wurman, J., and C. Alexander, 2005: The 30 May 1998 Spencer, South Dakota storm. Part II: Comparison of observed damage and radar-derived winds in the supercell tornadoes. Mon. Wea. Rev., 133, 97119.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., and K. A. Kosiba, 2008: DOW observations of multiple vortex structure in several tornadoes. Extended Abstracts, 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., P3.20. [Available online at https://ams.confex.com/ams/pdfpapers/142194.pdf.]

    • Search Google Scholar
    • Export Citation
  • Wurman, J., J. Straka, and E. Rasmussen, 1996: Fine-scale Doppler radar observation of tornadoes. Science , 272, 17741777.

  • Wurman, J., J. Straka, E. Rasmussen, M. Randall, and A. Zahrai, 1997: Design and deployment of a portable, pencil-beam, pulsed, 3-cm Doppler radar. J. Atmos. Oceanic Technol., 14, 15021512.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., C. Alexander, P. Robinson, and Y. Richardson, 2007a: Low-level winds in tornadoes and potential catastrophic tornado impacts in urban areas. Bull. Amer. Meteor. Soc., 88, 3146.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., Y. Richardson, C. Alexander, S. Weygandt, and P. F. Zhang, 2007b: Dual-Doppler and single-Doppler analysis of a tornadic storm undergoing mergers and repeated tornadogenesis. Mon. Wea. Rev., 135, 736758.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., Y. Richardson, C. Alexander, S. Weygandt, and P. F. Zhang, 2007c: Dual-Doppler analysis of winds and vorticity budget terms near a tornado. Mon. Wea. Rev., 135, 23922405.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., P. Robinson, W. Lee, C. R. Alexander, and K. A. Kosiba, 2008: Rapid-scan mobile radar 3D GBVTD and traditional analysis of tornadogenesis. Extended Abstracts, 24th Conf. on Severe Local Storms. Savannah, GA, Amer. Meteor. Soc., P13.6. [Available online at https://ams.confex.com/ams/24SLS/techprogram/paper_142176.htm.]

    • Search Google Scholar
    • Export Citation
  • Wurman, J., K. A. Kosiba, P. Markowski, Y. Richardson, D. Dowell, and P. Robinson, 2010: Finescale and dual- Doppler analysis of tornado intensification, maintenance, and dissipation in the Orleans, Nebraska, supercell. Mon. Wea. Rev., 138, 44394455.

    • Search Google Scholar
    • Export Citation
  • Wurman, J., D. Dowell, Y. Richardson, P. Markowski, E. Rasmussen, D. Burgess, L. Wicker, and H. B. Bluestein, 2012: The Second Verification of the Origins of Rotation in Tornadoes Experiment: VORTEX2. Bull. Amer. Meteor. Soc., 93, 11471170.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1582 622 57
PDF Downloads 1100 307 20