Comments on “A Climatology of Cell Mergers with Supercells and Their Association with Mesocyclone Evolution” and “The Influence of Cell Mergers on Supercell Characteristics and Tornado Evolution on 27–28 April 2011”

Jannick Fischer aDepartment Troposphere Research, Karlsruhe Institute of Technology, Karlsruhe, Germany

Search for other papers by Jannick Fischer in
Current site
Google Scholar
PubMed
Close
https://orcid.org/0000-0002-4314-7331
,
Matthew D. Flournoy bNOAA/NWS/NCEP Storm Prediction Center, University of Oklahoma, Norman, Oklahoma
cSchool of Meteorology, University of Oklahoma, Norman, Oklahoma
dCooperative Institute for Severe and High-Impact Weather Research and Operations, University of Oklahoma, Norman, Oklahoma

Search for other papers by Matthew D. Flournoy in
Current site
Google Scholar
PubMed
Close
, and
Anthony W. Lyza dCooperative Institute for Severe and High-Impact Weather Research and Operations, University of Oklahoma, Norman, Oklahoma
eNOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma

Search for other papers by Anthony W. Lyza in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Two recent articles investigated the evolution of supercell mesocyclone intensity during storm merger events using radar-indicated azimuthal shear. Both found that initially strong mesocyclones tended to weaken while initially weak mesocyclones statistically most frequently tended to intensify during the merger. However, these studies did not include null cases. In this article, random supercell periods are analyzed to test if a similar pattern of mesocyclone intensity variations happens in the absence of mergers. A similar pattern is found, suggesting that these intensity variations are stochastic rather than linked to merger events. Based on this finding, the datasets and conclusions of the previous two articles are reevaluated collaboratively.

© 2023 American Meteorological Society. This published article is licensed under the terms of the default AMS reuse license. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Jannick Fischer, jannick.fischer@kit.edu

Abstract

Two recent articles investigated the evolution of supercell mesocyclone intensity during storm merger events using radar-indicated azimuthal shear. Both found that initially strong mesocyclones tended to weaken while initially weak mesocyclones statistically most frequently tended to intensify during the merger. However, these studies did not include null cases. In this article, random supercell periods are analyzed to test if a similar pattern of mesocyclone intensity variations happens in the absence of mergers. A similar pattern is found, suggesting that these intensity variations are stochastic rather than linked to merger events. Based on this finding, the datasets and conclusions of the previous two articles are reevaluated collaboratively.

© 2023 American Meteorological Society. This published article is licensed under the terms of the default AMS reuse license. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Jannick Fischer, jannick.fischer@kit.edu
Save
  • Fischer, J., and J. M. L. Dahl, 2023: Supercell-external storms and boundaries acting as catalysts for tornadogenesis. Mon. Wea. Rev., 151, 2338, https://doi.org/10.1175/MWR-D-22-0026.1.

    • Search Google Scholar
    • Export Citation
  • Flournoy, M. D., A. W. Lyza, M. A. Satrio, M. R. Diedrichsen, M. C. Coniglio, and S. Waugh, 2022: A climatology of cell mergers with supercells and their association with mesocyclone evolution. Mon. Wea. Rev., 150, 451461, https://doi.org/10.1175/MWR-D-21-0204.1.

    • Search Google Scholar
    • Export Citation
  • Homeyer, C. R., T. N. Sandmael, C. K. Potvin, and A. M. Murphy, 2020: Distinguishing characteristics of tornadic and nontornadic supercell storms from composite mean analyses of radar observations. Mon. Wea. Rev., 148, 50155040, https://doi.org/10.1175/MWR-D-20-0136.1.

    • Search Google Scholar
    • Export Citation
  • Lee, B. D., B. F. Jewett, and R. B. Wilhelmson, 2006: The 19 April 1996 Illinois tornado outbreak. Part II: Cell mergers and associated tornado incidence. Wea. Forecasting, 21, 449464, https://doi.org/10.1175/WAF943.1.

    • Search Google Scholar
    • Export Citation
  • Lyza, A. W., and M. D. Flournoy, 2023: The influence of cell mergers on supercell characteristics and tornado evolution on 27–28 April 2011. Mon. Wea. Rev., 151, 15511569, https://doi.org/10.1175/MWR-D-22-0189.1.

    • Search Google Scholar
    • Export Citation
  • Markowski, P. M., T. P. Hatlee, and Y. P. Richardson, 2018: Tornadogenesis in the 12 May 2010 supercell thunderstorm intercepted by VORTEX2 near Clinton, Oklahoma. Mon. Wea. Rev., 146, 36233650, https://doi.org/10.1175/MWR-D-18-0196.1.

    • Search Google Scholar
    • Export Citation
  • Murphy, A. M., C. R. Homeyer, and K. Q. Allen, 2023: Development and investigation of GridRad-Severe, a multiyear severe event radar dataset. Mon. Wea. Rev., https://doi.org/10.1175/MWR-D-23-0017.1, in press.

    • Search Google Scholar
    • Export Citation
  • Skinner, P. S., C. C. Weiss, M. M. French, H. B. Bluestein, P. M. Markowski, and Y. P. Richardson, 2014: VORTEX2 observations of a low-level mesocyclone with multiple internal rear-flank downdraft momentum surges in the 18 May 2010 Dumas, Texas, supercell. Mon. Wea. Rev., 142, 29352960, https://doi.org/10.1175/MWR-D-13-00240.1.

    • Search Google Scholar
    • Export Citation
  • Stratman, D. R., and K. A. Brewster, 2017: Sensitivities of 1-km forecasts of 24 May 2011 tornadic supercells to microphysics parameterizations. Mon. Wea. Rev., 145, 26972721, https://doi.org/10.1175/MWR-D-16-0282.1.

    • Search Google Scholar
    • Export Citation
  • Williams, S. S., K. L. Ortega, and T. M. Smith, 2022: Multi-Year Reanalysis of Remotely Sensed Storms/MYRORSS_Data. OSF, accessed 6 March 2023, https://osf.io/9gzp2.

All Time Past Year Past 30 Days
Abstract Views 4167 4167 28
Full Text Views 283 283 3
PDF Downloads 271 271 8