• Adlerman, E. J., , and K. K. Droegemeier, 2002: The sensitivity of numerically simulated cyclic mesocyclogenesis to variations in model physical and computational parameters. Mon. Wea. Rev., 130 , 26712691.

    • Search Google Scholar
    • Export Citation
  • Adlerman, E. J., , K. K. Droegemeier, , and R. Davies-Jones, 1999: A numerical simulation of cyclic mesocyclogenesis. J. Atmos. Sci., 56 , 20452069.

    • Search Google Scholar
    • Export Citation
  • Arnott, N., , Y. Richardson, , J. Wurman, , and E. N. Rasmussen, 2006: Relationship between a weakening cold front, misocyclones, and cloud development on 10 June 2002 during IHOP. Mon. Wea. Rev., 134 , 311335.

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

  • Biggerstaff, M. I., and Coauthors, 2005: The Shared Mobile Atmospheric Research and Teaching (SMART) radar: A collaboration to enhance research and teaching. Bull. Amer. Meteor. Soc., 86 , 12631274.

    • Search Google Scholar
    • Export Citation
  • Brooks, H. E., , C. A. Doswell, , and J. Cooper, 1994: On the environments of tornadic and nontornadic mesocyclones. Wea. Forecasting, 9 , 606618.

    • Search Google Scholar
    • Export Citation
  • Brooks, H. E., , M. T. Carr, , and J. E. Ruthford, 1996: Preliminary analysis of soundings from VORTEX-95. Preprints, 18th Conf. on Severe Local Storms, San Francisco, CA, Amer. Meteor. Soc., 133–136.

  • Bunkers, M. J., , B. A. Klimowski, , J. W. Zeitler, , R. L. Thompson, , and M. L. Weisman, 2000: Predicting supercell motion using a new hodograph technique. Wea. Forecasting, 15 , 6179.

    • Search Google Scholar
    • Export Citation
  • Carpenter, R. L., , K. K. Droegemeier, , and A. M. Blyth, 1998: Entrainment and detrainment in numerically simulated cumulus congestus clouds. Part I: General results. J. Atmos. Sci., 55 , 34173432.

    • Search Google Scholar
    • Export Citation
  • Chandrasekhar, S., 1961: Hydrodynamic and Hydromagnetic Stability. Oxford University Press, 652 pp.

  • Christopherson, D. G., 1940: Note on the vibration of membranes. Quart. J. Math., 11 , Oxford Series. 6365.

  • Cotton, W. R., , and R. A. Anthes, 1989: Storm and Cloud Dynamics. Academic Press, 883 pp.

  • Davies-Jones, R. P., , D. Burgess, , and M. Foster, 1990: Test of helicity as a tornado forecast parameter. Preprints, 16th Conf. on Severe Local Storms, Kananaskis Park, Alberta, Canada, Amer. Meteor. Soc., 588–592.

  • Emanuel, K. A., 1994: Atmospheric Convection. Oxford University Press, 580 pp.

  • Grasso, L. D., , and W. R. Cotton, 1995: Numerical simulation of a tornado vortex. J. Atmos. Sci., 52 , 11921203.

  • James, R. P., , P. M. Markowski, , and J. M. Fritsch, 2006: Bow echo sensitivity to ambient moisture and cold pool strength. Mon. Wea. Rev., 134 , 950964.

    • Search Google Scholar
    • Export Citation
  • Kessinger, C. J., , P. S. Ray, , and C. E. Hane, 1987: The Oklahoma squall line of 19 May 1977. Part I: A multiple Doppler analysis of convective and stratiform structure. J. Atmos. Sci., 44 , 28402864.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., , and R. Rotunno, 1983: A study of the tornadic region within a supercell thunderstorm. J. Atmos. Sci., 40 , 359377.

  • Klemp, J. B., , R. B. Wilhelmson, , and P. S. Ray, 1981: Observed and numerically simulated structure of a mature supercell thunderstorm. J. Atmos. Sci., 38 , 15581580.

    • Search Google Scholar
    • Export Citation
  • Kost, J., , and Y. P. Richardson, 2004: The influence of temporally-varying vertical wind shear on numerically simulated convective storms. Preprints, 22d Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., CD-ROM, 9.2.

  • Kron, J., 2004: The evolution of numerically modeled convection in an environment containing horizontal variations of vertical shear and low-level moisture. M.S. thesis, Department of Meteorology, The Pennsylvania State University, 170 pp.

  • LeMone, M. A., 1973: The structure and dynamics of horizontal roll vortices in the planetary boundary layer. J. Atmos. Sci., 30 , 10771091.

    • Search Google Scholar
    • Export Citation
  • Markowski, P. M., , and Y. P. Richardson, 2004: Multiple-Doppler radar observations of vertical wind profile heterogeneity in convective boundary layers. Preprints, 22d Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., CD-ROM, P13.1.

  • Markowski, P. M., , J. M. Straka, , E. N. Rasmussen, , and D. O. Blanchard, 1998: Variability of storm-relative helicity during VORTEX. Mon. Wea. Rev., 126 , 29592971.

    • Search Google Scholar
    • Export Citation
  • Markowski, P. M., , C. Hannon, , and E. Rasmussen, 2006: Observations of convection initiation “failure” from the 12 June 2002 IHOP deployment. Mon. Wea. Rev., 134 , 375405.

    • 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., in press.

    • Search Google Scholar
    • Export Citation
  • Matejka, T., 2002: Estimating the most steady frame of reference from Doppler radar data. J. Atmos. Oceanic Technol., 19 , 10351048.

  • McCaul Jr., E. W., , and M. L. Weisman, 2001: The sensitivity of simulated supercell structure and intensity to variations in the shapes of environmental buoyancy and shear profiles. Mon. Wea. Rev., 129 , 664687.

    • Search Google Scholar
    • Export Citation
  • McCaul Jr, E. W., , and C. Cohen, 2002: The impact on simulated storm structure and intensity of variations in the mixed layer and moist layer depths. Mon. Wea. Rev., 130 , 17221748.

    • Search Google Scholar
    • Export Citation
  • Murphey, H. V., , R. M. Wakimoto, , C. N. Flamant, , and D. E. Kingsmill, 2006: The dryline on 19 June 2002 during IHOP. Part I: Airborne Doppler and LEANDRE II analyses of the thin line structure and convection initiation. Mon. Wea. Rev., 134 , 406430.

    • Search Google Scholar
    • Export Citation
  • Pauley, P. M., , and X. Wu, 1990: The theoretical, discrete, and actual response of the Barnes objective analysis scheme for one- and two-dimensional fields. Mon. Wea. Rev., 118 , 11451163.

    • Search Google Scholar
    • Export Citation
  • Rasmussen, E. N., , and R. B. Wilhelmson, 1983: Relationships between storm characteristics and 1200 GMT hodographs, low-level shear, and stability. Preprints, 13th Conf. on Severe Local Storms, Tulsa, OK, Amer. Meteor. Soc., J5–J8.

  • Rasmussen, E. N., , and D. O. Blanchard, 1998: A baseline climatology of sounding-derived supercell and tornado forecast parameters. Wea. Forecasting, 13 , 11481164.

    • Search Google Scholar
    • Export Citation
  • Rasmussen, E. N., , J. M. Straka, , R. P. Davies-Jones, , C. A. Doswell, , F. H. Carr, , M. D. Eilts, , and D. R. MacGorman, 1994: Verification of the Origins of Rotation in Tornadoes Experiment: VORTEX. Bull. Amer. Meteor. Soc., 75 , 9951006.

    • Search Google Scholar
    • Export Citation
  • Richardson, Y. P., 1999: The influence of horizontal variations in vertical shear and low-level moisture on numerically simulated convective storms. Ph.D. dissertation, University of Oklahoma, Norman, Oklahoma, 236 pp.

  • Richardson, Y. P., , J. Marquis, , E. N. Rasmussen, , J. M. Wurman, , and N. R. Arnott, 2004: Analysis of convection initiation along a dryline on 19 June 2002. Preprints, 22d Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., CD-ROM, 16A.4.

  • Richardson, Y. P., , K. K. Droegemeier, , and R. P. Davies-Jones, 2007: The influence of horizontal environmental variability on numerically simulated convective storms. Part I: Variations in vertical shear. Mon. Wea. Rev., in press.

    • Search Google Scholar
    • Export Citation
  • Stonitsch, J. R., , and P. M. Markowski, 2007: Unusually long-duration, multiple-Doppler radar observations of a front in a convective boundary layer. Mon. Wea. Rev., 135 , 93117.

    • Search Google Scholar
    • Export Citation
  • Straka, J. M., , E. N. Rasmussen, , and S. E. Fredrickson, 1996: A mobile mesonet for finescale meteorological observations. J. Atmos. Oceanic Technol., 13 , 921936.

    • Search Google Scholar
    • Export Citation
  • Thompson, R. L., , R. Edwards, , J. A. Hart, , K. L. Elmore, , and P. M. Markowski, 2003: Close proximity soundings within supercell environments obtained from the Rapid Update Cycle. Wea. Forecasting, 18 , 12431261.

    • Search Google Scholar
    • Export Citation
  • Trapp, R. J., , and C. A. Doswell III, 2000: Radar data objective analysis. J. Atmos. Oceanic Technol., 17 , 105120.

  • Weckwerth, T. M., , J. W. Wilson, , and R. M. Wakimoto, 1996: Thermodynamic variability within the convective boundary layer due to horizontal convective rolls. Mon. Wea. Rev., 124 , 769784.

    • Search Google Scholar
    • Export Citation
  • Weckwerth, T. M., , J. W. Wilson, , R. M. Wakimoto, , and N. A. Crook, 1997: Horizontal convective rolls: Determining the environmental conditions supporting their existence and characteristics. Mon. Wea. Rev., 125 , 505526.

    • Search Google Scholar
    • Export Citation
  • Weckwerth, T. M., and Coauthors, 2004: An overview of the International H2O Project (IHOP) and some preliminary highlights. Bull. Amer. Meteor. Soc., 85 , 253277.

    • Search Google Scholar
    • Export Citation
  • 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
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Observations of Vertical Wind Shear Heterogeneity in Convective Boundary Layers

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  • 1 Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania
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Abstract

Dual-Doppler wind syntheses from mobile radar observations obtained during the International H2O Project document some of the spatial variability of vertical wind profiles in convective boundary layers. Much of the variability of popular forecasting parameters such as vertical wind shear magnitude and storm-relative helicity is thought to result from pressure and temperature gradients associated with mesoscale boundaries (e.g., drylines, outflow boundaries, fronts). These analyses also reveal substantial heterogeneity even in the absence of obvious mesoscale wind shifts—in regions many might have classified as “horizontally homogeneous” with respect to these parameters in the past. This heterogeneity is closely linked to kinematic perturbations associated with boundary layer convection. When a mean wind is present, the large spatial variability implies significant temporal variability in the vertical wind profiles observed at fixed locations, with the temporal variability increasing with mean wind speed. Significant differences also can arise between true hodographs and “pseudohodographs” obtained from rawinsondes that are advected horizontally as they ascend. Some possible implications of the observed heterogeneity with respect to forecasting and simulating convective storms also are discussed.

Corresponding author address: Dr. Paul Markowski, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802. Email: pmarkowski@psu.edu

Abstract

Dual-Doppler wind syntheses from mobile radar observations obtained during the International H2O Project document some of the spatial variability of vertical wind profiles in convective boundary layers. Much of the variability of popular forecasting parameters such as vertical wind shear magnitude and storm-relative helicity is thought to result from pressure and temperature gradients associated with mesoscale boundaries (e.g., drylines, outflow boundaries, fronts). These analyses also reveal substantial heterogeneity even in the absence of obvious mesoscale wind shifts—in regions many might have classified as “horizontally homogeneous” with respect to these parameters in the past. This heterogeneity is closely linked to kinematic perturbations associated with boundary layer convection. When a mean wind is present, the large spatial variability implies significant temporal variability in the vertical wind profiles observed at fixed locations, with the temporal variability increasing with mean wind speed. Significant differences also can arise between true hodographs and “pseudohodographs” obtained from rawinsondes that are advected horizontally as they ascend. Some possible implications of the observed heterogeneity with respect to forecasting and simulating convective storms also are discussed.

Corresponding author address: Dr. Paul Markowski, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802. Email: pmarkowski@psu.edu

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