High-Temporal Resolution Observations of the 27 May 2015 Canadian, Texas, Tornado Using the Atmospheric Imaging Radar

Casey B. Griffin School of Meteorology, and Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

Search for other papers by Casey B. Griffin in
Current site
Google Scholar
PubMed
Close
,
David J. Bodine Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

Search for other papers by David J. Bodine in
Current site
Google Scholar
PubMed
Close
,
James M. Kurdzo Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

Search for other papers by James M. Kurdzo in
Current site
Google Scholar
PubMed
Close
,
Andrew Mahre School of Meteorology, and Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

Search for other papers by Andrew Mahre in
Current site
Google Scholar
PubMed
Close
, and
Robert D. Palmer School of Meteorology, and Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

Search for other papers by Robert D. Palmer in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

On 27 May 2015, the Atmospheric Imaging Radar (AIR) collected high-temporal resolution radar observations of an EF-2 tornado near Canadian, Texas. The AIR is a mobile, X-band, imaging radar that uses digital beamforming to collect simultaneous RHI scans while steering mechanically in azimuth to obtain rapid-update weather data. During this deployment, 20°-by-80° (elevation × azimuth) sector volumes were collected every 5.5 s at ranges as close as 6 km. The AIR captured the late-mature and decaying stages of the tornado. Early in the deployment, the tornado had a radius of maximum winds (RMW) of 500 m and exhibited maximum Doppler velocities near 65 m s−1. This study documents the rapid changes associated with the dissipation stages of the tornado. A 10-s resolution time–height investigation of vortex tilt and differential velocity is presented and illustrates an instance of upward vortex intensification as well as downward tornado decay. Changes in tornado intensity over periods of less than 30 s coincided with rapid changes in tornado diameter. At least two small-scale vortices were observed being shed from the tornado during a brief weakening period. A persistent layer of vortex tilt was observed near the level of free convection, which separated two layers with contrasting modes of tornado decay. Finally, the vertical cross correlation of vortex intensity reveals that apart from the brief instances of upward vortex intensification and downward decay, tornado intensity was highly correlated throughout the observation period.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Casey B. Griffin, casey.griffin@ou.edu

Abstract

On 27 May 2015, the Atmospheric Imaging Radar (AIR) collected high-temporal resolution radar observations of an EF-2 tornado near Canadian, Texas. The AIR is a mobile, X-band, imaging radar that uses digital beamforming to collect simultaneous RHI scans while steering mechanically in azimuth to obtain rapid-update weather data. During this deployment, 20°-by-80° (elevation × azimuth) sector volumes were collected every 5.5 s at ranges as close as 6 km. The AIR captured the late-mature and decaying stages of the tornado. Early in the deployment, the tornado had a radius of maximum winds (RMW) of 500 m and exhibited maximum Doppler velocities near 65 m s−1. This study documents the rapid changes associated with the dissipation stages of the tornado. A 10-s resolution time–height investigation of vortex tilt and differential velocity is presented and illustrates an instance of upward vortex intensification as well as downward tornado decay. Changes in tornado intensity over periods of less than 30 s coincided with rapid changes in tornado diameter. At least two small-scale vortices were observed being shed from the tornado during a brief weakening period. A persistent layer of vortex tilt was observed near the level of free convection, which separated two layers with contrasting modes of tornado decay. Finally, the vertical cross correlation of vortex intensity reveals that apart from the brief instances of upward vortex intensification and downward decay, tornado intensity was highly correlated throughout the observation period.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Casey B. Griffin, casey.griffin@ou.edu
Save
  • Alexander, C., and J. Wurman, 2008: Updated mobile radar climatology of supercell tornado structure and dynamics. 24th Conf. on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 19.4, https://ams.confex.com/ams/24SLS/techprogram/paper_141821.htm.

  • Atkins, N. T., A. McGee, R. Ducharme, R. M. Wakimoto, and J. Wurman, 2012: The LaGrange tornado during VORTEX2. Part II: Photogrammetric analysis of the tornado combined with dual-Doppler radar data. Mon. Wea. Rev., 140, 29392958, https://doi.org/10.1175/MWR-D-11-00285.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., and A. 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, 29392951, https://doi.org/10.1175/1520-0477(2000)081<2939:OOTAOC>2.3.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 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, https://doi.org/10.1175/1520-0493(2003)131<2968:MDROOA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., M. M. French, R. L. Tanamachi, S. Frasier, K. Hardwick, F. Junyent, and A. Pazmany, 2007a: Close-range observations of tornadoes in supercells made with a dual-polarization, X-band, mobile Doppler radar. Mon. Wea. Rev., 135, 15221543, https://doi.org/10.1175/MWR3349.1.

    • Crossref
    • 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, 2007b: The structure of tornadoes near Attica, Kansas on 12 May 2004: High-resolution, mobile, Doppler radar observations. Mon. Wea. Rev., 135, 475506, https://doi.org/10.1175/MWR3295.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., M. French, I. PopStefanija, R. Bluth, and J. Knorr, 2010: A mobile, phased-array Doppler radar for the study of severe convective storms. Bull. Amer. Meteor. Soc., 91, 579600, https://doi.org/10.1175/2009BAMS2914.1.

    • Crossref
    • 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, 15011524, https://doi.org/10.1175/MWR2934.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • French, M., H. Bluestein, I. PopStefanija, C. Baldi, and R. Bluth, 2013: Reexamining the vertical development of tornadic vortex signatures in supercells. Mon. Wea. Rev., 141, 45764601, https://doi.org/10.1175/MWR-D-12-00315.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • French, M., H. Bluestein, I. PopStefanija, C. Baldi, and R. Bluth, 2014: Mobile, phased-array, Doppler radar observations of tornadoes at X band. Mon. Wea. Rev., 142, 10101036, https://doi.org/10.1175/MWR-D-13-00101.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gall, R. L., 1983: A linear analysis of the multiple vortex phenomenon in simulated tornadoes. J. Atmos. Sci., 40, 20102024, https://doi.org/10.1175/1520-0469(1983)040<2010:ALAOTM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Houser, J., H. Bluestein, and J. Snyder, 2015: Rapid-scan, polarimetric, Doppler radar observations of tornadogenesis and tornado dissipation in a tornadic supercell: The “El Reno, Oklahoma” storm of 24 May 2011. Mon. Wea. Rev., 143, 26852710, https://doi.org/10.1175/MWR-D-14-00253.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Houser, J. L., H. B. Bluestein, and J. Snyder, 2016: A finescale radar examination of the tornadic debris signature and weak-echo reflectivity band associated with a large, violent tornado. Mon. Wea. Rev., 144, 41014130, https://doi.org/10.1175/MWR-D-15-0408.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Isom, B., and Coauthors, 2013: The Atmospheric Imaging Radar: Simultaneous volumetric observations using a phased array weather radar. J. Atmos. Oceanic Technol., 30, 655675, https://doi.org/10.1175/JTECH-D-12-00063.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kosiba, K. A., and J. M. Wurman, 2013: The three-dimensional structure and evolution of a tornado boundary layer. Wea. Forecasting, 28, 15521561, https://doi.org/10.1175/WAF-D-13-00070.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kurdzo, J. M., B. L. Cheong, R. D. Palmer, G. Zhang, and J. Meier, 2014: A pulse compression waveform for improved-sensitivity weather radar observations. J. Atmos. Oceanic Technol., 31, 27132731, https://doi.org/10.1175/JTECH-D-13-00021.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kurdzo, J. M., D. J. Bodine, B. L. Cheong, and R. D. Palmer, 2015: High-temporal resolution polarimetric X-band Doppler radar observations of the 20 May 2013 Moore, Oklahoma, tornado. Mon. Wea. Rev., 143, 27112735, https://doi.org/10.1175/MWR-D-14-00357.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kurdzo, J. M., and Coauthors, 2017: Observations of severe local storms and tornadoes with the Atmospheric Imaging Radar. Bull. Amer. Meteor. Soc., 98, 915935, https://doi.org/10.1175/BAMS-D-15-00266.1.

    • Crossref
    • 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, https://doi.org/10.1175/1520-0469(2000)057<0527:TIOALS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mahre, A., J. M. Kurdzo, D. J. Bodine, C. B. Griffin, R. D. Palmer, and T.-Y. Yu, 2018: Analysis of the 16 May 2015 Tipton, Oklahoma, EF-3 tornado at high spatiotemporal resolution using the Atmospheric Imaging Radar. Mon. Wea. Rev., 146, 21032124, https://doi.org/10.1175/MWR-D-17-0256.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marquis, J., Y. Richardson, P. Markowski, D. Dowell, and J. Wurman, 2012: Tornado maintenance investigated with high-resolution dual-Doppler and EnKF analysis. Mon. Wea. Rev., 140, 327, https://doi.org/10.1175/MWR-D-11-00025.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marquis, J., Y. Richardson, P. Markowski, J. Wurman, K. Kosiba, and P. Robinson, 2016: An investigation of the Goshen County, Wyoming, tornadic supercell of 5 June 2009 using EnKF assimilation of mobile mesonet and radar observations collected during VORTEX2. Part II: Mesocyclone-scale processes affecting tornado formation, mainenance, and decay. Mon. Wea. Rev., 144, 34413463, https://doi.org/10.1175/MWR-D-15-0411.1.

    • Search Google Scholar
    • Export Citation
  • Mead, J., G. Hopcraft, S. J. Frasier, B. D. Pollar, C. D. Cherry, D. H. Schaubert, and R. E. McIntosh, 1998: A volume-imaging radar wind profiler for atmospheric boundary layer turbulence studies. J. Atmos. Oceanic Technol., 15, 849859, https://doi.org/10.1175/1520-0426(1998)015<0849:AVIRWP>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pazmany, A., J. Mead, H. Bluestein, J. Snyder, and J. Houser, 2013: A mobile rapid-scanning X-band polarimetric (RaXPol) Doppler radar system. J. Atmos. Oceanic Technol., 30, 13981413, https://doi.org/10.1175/JTECH-D-12-00166.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rasmussen, E., and J. Straka, 2007: Evolution of low-level angular momentum in the 2 June 1995 Dimmitt, Texas, tornado cyclone. J. Atmos. Sci., 64, 13651378, https://doi.org/10.1175/JAS3829.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., 1978: A note on the stability of a cylindrical vortex sheet. J. Fluid Mech., 87, 761771, https://doi.org/10.1017/S0022112078001871.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Salazar-Cerreño, J. L., and Coauthors, 2017: Development of a mobile C-band polarimetric atmospheric imaging radar (PAIR). Special Symp. on Meteorological Observations and Instrumentation, Seattle, WA, Amer. Meteor. Soc., 1B.1, https://ams.confex.com/ams/97Annual/webprogram/Paper308655.html.

  • Snyder, J., and H. Bluestein, 2014: Some considerations for the use of high-resolution mobile radar data in tornado intensity determination. Wea. Forecasting, 29, 799827, https://doi.org/10.1175/WAF-D-14-00026.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tanamachi, R. L., H. B. Bluestein, W. C. Lee, M. Bell, and A. L. Pazmany, 2007: Ground-based velocity track display (GBVTD) analysis of W-band radar data in a tornado near Stockton, Kansas, on 15 May 1999. Mon. Wea. Rev., 135, 783800, https://doi.org/10.1175/MWR3325.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tanamachi, R. L., H. B. Bluestein, J. B. Houser, S. J. Frasier, and K. M. Hardwick, 2012: Mobile X-band, polarimetric Doppler radar observations of the 4 May 2007 Greensburg, Kansas, tornadic supercell. Mon. Wea. Rev., 140, 21032125, https://doi.org/10.1175/MWR-D-11-00142.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tanamachi, R. L., H. B. Bluestein, M. Xue, W. C. Lee, K. Orzel, S. Frasier, and R. M. Wakimoto, 2013: Near-surface vortex structure in a tornado and in a sub-tornado-strength convective-storm vortex observed by a mobile, W-band radar during VORTEX2. Mon. Wea. Rev., 141, 36613690, https://doi.org/10.1175/MWR-D-12-00331.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., and Coauthors, 2016: Aerial damage survey of the 2013 El Reno tornado combined with mobile radar data. Mon. Wea. Rev., 144, 17491776, https://doi.org/10.1175/MWR-D-15-0367.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weiss, C. C., T. Cermak, R. Metzger, A. Reinhart, and P. Skinner, 2014: Insights into tornado structure afforded by high-frequency mobile radar. 27th Conf. on Severe Local Storms, Madison, WI, Amer. Meteor. Soc., P9.4, https://ams.confex.com/ams/27SLS/webprogram/Paper255350.html.

  • Wurman, J., 2002: The multiple-vortex structure of a tornado. Wea. Forecasting, 17, 473505, https://doi.org/10.1175/1520-0434(2002)017<0473:TMVSOA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wurman, J., and S. Gill, 2000: Fine-scale radar observations of the Dimmitt, Texas (2 June 1995), tornado. Mon. Wea. Rev., 128, 21352164, https://doi.org/10.1175/1520-0493(2000)128<2135:FROOTD>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wurman, J., and M. Randall, 2001: An inexpensive, mobile, rapid-scan radar. Preprints, 30th Int. Conf. on Radar Meteorology, Munich, Germany, Amer. Meteor. Soc., P3.4, https://ams.confex.com/ams/30radar/techprogram/paper_21577.htm.

  • Wurman, J., and K. Kosiba, 2013: Finescale radar observations of tornadoes and mesocyclone structures. Wea. Forecasting, 28, 11571174, https://doi.org/10.1175/WAF-D-12-00127.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wurman, J., J. Straka, and E. Rasmussen, 1996: Fine-scale Doppler radar observations of tornadoes. Science, 272, 17741777, https://doi.org/10.1126/science.272.5269.1774.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wurman, J., Y. Richardson, C. Alexander, S. Weygandt, and P. F. Zhang, 2007: Dual-Doppler and single-Doppler analysis of a tornadic storm undergoing mergers and repeated tornadogenesis. Mon. Wea. Rev., 135, 736758, https://doi.org/10.1175/MWR3276.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wurman, J., K. 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, 835846, https://doi.org/10.1175/BAMS-D-12-00114.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 570 127 7
PDF Downloads 613 129 10