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David J. Kellenbenz NOAA/National Weather Service/Eastern North Dakota Weather Forecast Office, Grand Forks, North Dakota

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Thomas J. Grafenauer NOAA/National Weather Service/Eastern North Dakota Weather Forecast Office, Grand Forks, North Dakota

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Jonathan M. Davies Trimble/Kansas City, Missouri

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Abstract

Edwards and Thompson have made comprehensive and thorough comments concerning the methods, accuracy, and results in a case study by Kellenbenz et al. These comments questioned the representativeness of model-derived soundings and graphics used, as well as the modification methods employed with soundings presented in the 18 July 2004 case study. Other issues included the application of previous database studies to lifting condensation level (LCL) values found in the 18 July 2004 examination, as well as a focus that emphasized a single tornadic storm. In this response, the authors address problems and oversights with the 18 July 2004 case study, using new data to conduct a reanalysis of the environment on that evening. Additionally, a large independent database of Rapid Update Cycle (RUC) analysis soundings associated with supercell tornadoes is used to provide the context from which to carefully evaluate LCL results from the 18 July 2004 case relative to significant and violent tornadoes. Results indicate that although the LCL height associated with the F4 tornadic supercell in the original case study was probably overestimated, the background LCL environment was still unusually high for a violent tornado. New material presented in this response reinforces the conclusion that, when LCL heights are at the far upper end of empirical study distributions associated with significant tornadoes, undue weight should not be given to LCL as a tornado probability reduction factor when CAPE–storm relative helicity (SRH) combinations and deep-layer shear are also strong.

Corresponding author address: Jonathan M. Davies, 9101 Alpha Ridge Rd., Trimble, MO 64492. Email: davieswx@gmail.com

Abstract

Edwards and Thompson have made comprehensive and thorough comments concerning the methods, accuracy, and results in a case study by Kellenbenz et al. These comments questioned the representativeness of model-derived soundings and graphics used, as well as the modification methods employed with soundings presented in the 18 July 2004 case study. Other issues included the application of previous database studies to lifting condensation level (LCL) values found in the 18 July 2004 examination, as well as a focus that emphasized a single tornadic storm. In this response, the authors address problems and oversights with the 18 July 2004 case study, using new data to conduct a reanalysis of the environment on that evening. Additionally, a large independent database of Rapid Update Cycle (RUC) analysis soundings associated with supercell tornadoes is used to provide the context from which to carefully evaluate LCL results from the 18 July 2004 case relative to significant and violent tornadoes. Results indicate that although the LCL height associated with the F4 tornadic supercell in the original case study was probably overestimated, the background LCL environment was still unusually high for a violent tornado. New material presented in this response reinforces the conclusion that, when LCL heights are at the far upper end of empirical study distributions associated with significant tornadoes, undue weight should not be given to LCL as a tornado probability reduction factor when CAPE–storm relative helicity (SRH) combinations and deep-layer shear are also strong.

Corresponding author address: Jonathan M. Davies, 9101 Alpha Ridge Rd., Trimble, MO 64492. Email: davieswx@gmail.com

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