Editorial Type:
Article
Article Type:
Research Article

The Role of Multiple-Vortex Tornado Structure in Causing Storm Researcher Fatalities

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
,
Paul Robinson Center for Severe Weather Research, Boulder, Colorado

Search for other papers by Paul Robinson in
Current site
Google Scholar
PubMed Close
, and
Tim Marshall Haag Engineering, Irving, Texas

Search for other papers by Tim Marshall in
Current site
Google Scholar
PubMed Close
Online Publication:
01 Jan 2014
Print Publication:
01 Jan 2014
DOI:
https://doi.org/10.1175/BAMS-D-13-00221.1
Page(s):
31–45
Restricted access

We are aware of a technical issue preventing figures and tables from showing in some newly published articles in the full-text HTML view.
While we are resolving the problem, please use the online PDF version of these articles to view figures and tables.

A large and violent tornado/multiple-vortex mesocyclone (MVMC) tracked east and northeastward near El Reno, Oklahoma, on 31 May 2013, causing eight fatalities, including storm chasers/researchers attempting to deploy in situ instrumentation. Subvortices moved within and near the MVMC, some in trochoidal-like patterns, with ground-relative translational velocities ranging from 0 to 79 m s−1, the fastest ever documented. Doppler on Wheels (DOW) measurements in one of these subvortices exceeded 115 m s−1 at 114 m AGL. With assumptions concerning radar-unobserved components of the velocity, peak wind speeds of 130–150 m s−1 are implied, comparable to the strongest ever measured. Only enhanced Fujita scale 3 (EF-3) damage was documented, likely because of a paucity of well-built structures and the most intense winds being confined to small, rapidly moving subvortices, resulting in only subsecond gusts. The region enclosing the maximum winds of the tornado/MVMC extended ~2 km. DOW-measured winds > 50 m s−1 (> 30 m s−1) extended far beyond the radius of maximum winds (RMW) extending >5 km (7 km), comparable to the widest ever documented. A strong multiple-vortex anticyclonic tornado with dual-polarization debris signatures is documented.

A subvortex tracking eastward within the larger tornado/MVMC intensified, moved north, and then moved northwestward, becoming briefly nearly stationary near/over a research team's vehicle, transporting it ~600 m generally eastward, killing the team. An experienced media team's vehicle was destroyed inside the tornado/MVMC, resulting in injuries. The circumstances leading to these incidents are analyzed using DOW data. The anomalous—and likely unpredictable in real time—path of the interior subvortex likely contributed to these deaths and injuries. The risks associated with chasing and scientific missions near and particularly inside large and complex MVMC/tornado vortices are discussed.

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

A large and violent tornado/multiple-vortex mesocyclone (MVMC) tracked east and northeastward near El Reno, Oklahoma, on 31 May 2013, causing eight fatalities, including storm chasers/researchers attempting to deploy in situ instrumentation. Subvortices moved within and near the MVMC, some in trochoidal-like patterns, with ground-relative translational velocities ranging from 0 to 79 m s−1, the fastest ever documented. Doppler on Wheels (DOW) measurements in one of these subvortices exceeded 115 m s−1 at 114 m AGL. With assumptions concerning radar-unobserved components of the velocity, peak wind speeds of 130–150 m s−1 are implied, comparable to the strongest ever measured. Only enhanced Fujita scale 3 (EF-3) damage was documented, likely because of a paucity of well-built structures and the most intense winds being confined to small, rapidly moving subvortices, resulting in only subsecond gusts. The region enclosing the maximum winds of the tornado/MVMC extended ~2 km. DOW-measured winds > 50 m s−1 (> 30 m s−1) extended far beyond the radius of maximum winds (RMW) extending >5 km (7 km), comparable to the widest ever documented. A strong multiple-vortex anticyclonic tornado with dual-polarization debris signatures is documented.

A subvortex tracking eastward within the larger tornado/MVMC intensified, moved north, and then moved northwestward, becoming briefly nearly stationary near/over a research team's vehicle, transporting it ~600 m generally eastward, killing the team. An experienced media team's vehicle was destroyed inside the tornado/MVMC, resulting in injuries. The circumstances leading to these incidents are analyzed using DOW data. The anomalous—and likely unpredictable in real time—path of the interior subvortex likely contributed to these deaths and injuries. The risks associated with chasing and scientific missions near and particularly inside large and complex MVMC/tornado vortices are discussed.

CORRESPONDING AUTHOR: Joshua Wurman, Center for Severe Weather Research, 1945 Vassar Circle, Boulder, CO 80305, E-mail: jwurman@cswr.org
Save
Cover Bulletin of the American Meteorological Society
Bulletin of the American Meteorological Society

  • Alexander, C. R., and J. Wurman, 2008: Updated mobile radar climatology of supercell tornado structures and dynamics, Proc. 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 19.4. [Available online at http://ams.confex.com/ams/pdfpapers/141821.pdf.]

    • Search Google Scholar
    • Export Citation

  • Bluestein, H. B., 1999: A history of storm-intercept field programs. Wea. Forecasting, 14, 558–577.

  • Bluestein, H. B., and A. Bedard, 1982: Surface meteorological observations in severe thunderstorms: Field measurements and design detail of TOTO. Proc. 12th Conf. on Severe Local Storms, San Antonio, TX, Amer. Meteor. Soc., 383–395.

    • Search Google Scholar
    • Export Citation

  • Bluestein, H. B., and A. L. Pazmany, 2000: Observations of tornadoes and other convective phenomena with a mobile, 3-mm wavelength, Doppler radar: The spring 1999 field experiment. Bull. Amer. Meteor. Soc., 81, 2939–2351.

    • Search Google Scholar
    • Export Citation

  • Bluestein, H. B., S. G. Gaddy, D. C. Dowell, A. L. Pazmany, J. C. Galloway, R. E. McIntosh, and H. Stein, 1997: Doppler radar observations of substorm-scale vortices in a supercell. Mon. Wea. Rev., 125, 1046–1059.

    • Search Google Scholar
    • Export Citation

  • Bluestein, H. B., 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 I: Tornadogenesis. Mon. Wea. Rev., 131, 2954–2967.

    • 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, mobile, W-band, Doppler radar observations. Mon. Wea. Rev., 132, 2325–2337.

    • Search Google Scholar
    • Export Citation

  • Bluestein, H. B., M. M. French, R. L. Tanamachi, S. Frasier, K. Hardwick, F. Junyent, and A. L. Pazmany, 2007: Close-range observations of tornadoes in supercells made with a dual-polarization, X-band, mobile Doppler radar. Mon. Wea. Rev., 135, 1522–1543.

    • Search Google Scholar
    • Export Citation

  • Brock, F. V., G. Lesins, and R. Walko, 1987: Measurement of pressure and air temperature near severe thunderstorms: An inexpensive and portable instrument. Extended abstracts, Sixth Symp. on Meteorological Observations and Instrumentation, New Orleans, LA, Amer. Meteor. Soc., 320–323.

    • 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., 133, 1501–1524.

    • Search Google Scholar
    • Export Citation

  • Hastings, R. M., Y. P. Richardson, P. Markowski, J. Wurman, and C. C. Weiss, 2012a: Mergers in supercell environments. Part I: Conceptual models of mechanisms governing merger outcomes. Preprints, 26th Conf. on Severe Local Storms, Nashville, TN, Amer. Meteor. Soc, 11B.6. [Available online at https://ams.confex.com/ams/26SLS/webprogram/Paper212519.html.]

    • Search Google Scholar
    • Export Citation

  • Hastings, R. M., Y. P. Richardson, and P. Markowski, 2012b: Mergers in supercell environments. Part II: Tornadogenesis potential during merger as evaluated by changes in the near-surface low-level mesocyclone. Preprints, 26th Conf. on Severe Local Storms, Nashville, TN, Amer. Meteor. Soc, P143. [Available online at https://ams.confex.com/ams/26SLS/webprogram/Paper212524.html.]

    • Search Google Scholar
    • Export Citation

  • Karstens, C. D., T. M. Samaras, B. D. Lee, W. A. Gallus Jr., and C. A. Finley, 2010: Near-ground pressure and wind measurements in tornadoes. Mon. Wea. Rev., 138, 2570–2588.

    • Search Google Scholar
    • Export Citation

  • Kosiba, K., and J. Wurman, 2010: The three-dimensional axisymmetric wind field structure of the Spencer, South Dakota, 1998 tornado. J. Atmos. Sci., 67, 3074–3083.

    • Search Google Scholar
    • Export Citation

  • Kosiba, K., and J. Wurman, 2013: The three-dimensional structure and evolution of a tornado boundary layer. Mon. Wea. Rev., 28, 1552–1561.

    • Search Google Scholar
    • Export Citation

  • Kosiba, K., 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., J. Wurman, Y. Richardson, P. Markowski, P. Robinson, and J. Marquis, 2013: Genesis of the Goshen County, Wyoming, tornado on 5 June 2009 during VORTEX2. Mon. Wea. Rev., 141, 1157–1181.

    • Search Google Scholar
    • Export Citation

  • Kumijan, M. R., 2011: Precipitation properties of supercell hook echoes. E-J. Severe Storms Meteor., 6, 1–21.

  • Lee, B. D., C. A. Finley, and T. M. Samaras, 2011: Surface analysis near and within the Tipton, Kansas, tornado on 29 May 2008. Mon. Wea. Rev., 139, 370–386.

    • Search Google Scholar
    • Export Citation

  • Lee, J. J., T. M. Samaras, and C. R. Young, 2004: Pressure measurements at the ground in an F-4 tornaado. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer, Meteor. Soc., 15.3.

    • Search Google Scholar
    • Export Citation

  • Lee, W.-C., and J. Wurman, 2005: The diagnosed structure of the Mulhall tornado. J. Atmos. Sci., 62, 2373–2393.

  • Marquis, J. N., Y. P. Richardson, J. M. Wurman, and P. M. Markowski, 2008: Single- and dual-Doppler analysis of a tornadic vortex and surrounding storm scale flow in the Crowell, TX, supercell of 30 April 2000. Mon. Wea. Rev., 136, 5017–5043.

    • Search Google Scholar
    • Export Citation

  • Ryzhkov, A. V., T. J. Schuur, D. W. Burgess, and D. S. Zrnic, 2005: Polarimetric tornado detection. J. Appl. Meteor., 44, 557–570.

  • Samaras, T. M., 2004: A historical perspective of in-situ observations within tornado cores. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., P11.4.

    • Search Google Scholar
    • Export Citation

  • Tanamachi, R. L., H. B. Bluestein, W.-C. Lee, M. Bell, and A. Pazmany, 2007: Ground-based velocity track display (GBVTD) analysis of W-band Doppler radar data in a tornado near Stockton, Kansas, on 15 May 1999. Mon. Wea. Rev., 135, 783–800.

    • Search Google Scholar
    • Export Citation

  • Tatom, F. B., and K. R. Knupp, 1995: Tornado detection based on seismic signal. J. Appl. Meteor., 34, 572.

  • van Doren, C., 1938: Benjamin Franklin. Viking Press, 845 pp.

  • 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, 3397–3418.

    • Search Google Scholar
    • Export Citation

  • Winn, W. P., S. J. Hunyady, and G. D. Aulich, 1999: Pressure at the ground in a large tornado. J. Geophys. Res., 104, 22 067–22 082.

  • Wurman, J., 2002: The multiple-vortex structure of a tornado. Wea. Forecasting, 17, 473–505.

  • Wurman, J., 2008: Preliminary results and report of the ROTATE-2008 radar/in-situ/mobile mesonet experiment. Preprints, 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 5.4.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., and S. Gill, 2000: Finescale radar observations of the Dimmitt, Texas (2 June 1995), tornado. Mon. Wea. Rev., 128, 2135–2164.

    • 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. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., 15.4. [Available online at http://ams.confex.com/ams/pdfpapers/82352.pdf.]

    • Search Google Scholar
    • Export Citation

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

    • Search Google Scholar
    • Export Citation

  • Wurman, J., and K. A. Kosiba, 2013: Finescale radar observations of tornado and mesocyclone structures. Wea. Forecasting, 28, 1157–1174.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., J. Straka, and E. Rasmussen, 1996: Fine Scale Doppler Radar Observation of Tornadoes. Science, 272, 1774–1777.

  • Wurman, J., J. Straka, E. Rasmussen, M. Randall, A. Zahrai, 1997: Design and Deployment of a Portable, Pencil-Beam, Pulsed Doppler Radar, J. Atmos. Oceanic. Technol., 14, 1502–1512.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., Y. Richardson, C. Alexander, S. Weygandt, and P. F. Zhang, 2007a: Dual-Doppler and single-Doppler analysis of a tornadic storm undergoing mergers and repeated tornadogenesis. Mon. Wea. Rev., 135, 736–758.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., P. Robinson, C. Alexander, and Y. Richardson, 2007b: Low-level winds in tornadoes and potential catastrophic tornado impacts in urban areas. Bull. Amer. Meteor. Soc., 88, 31–46.

    • 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, 1147–1170.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., K. A. Kosiba, and P. Robinson, 2013: In situ, Doppler radar, and video observations of the interior structure of a tornado and the wind–damage relationship. Bull. Amer. Meteor. Soc., 94, 835–846.

    • Search Google Scholar
    • Export Citation