• Atkins, N. T., M. L. Weisman, and L. J. Wicker, 1999: The influence of preexisting boundaries on supercell evolution. Mon. Wea. Rev., 127, 29102927.

    • Search Google Scholar
    • Export Citation
  • Biggerstaff, M. I., and Coauthors, 1997: The Texas A&M University convection and lightning experiment—TEXACAL 97. Preprints, 28th Conf. on Radar Meteorology, Austin, TX, Amer. Meteor. Soc., 588–589.

    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., and M. H. Jain, 1985: Formation of mesoscale lines of precipitation: Severe squall lines in Oklahoma during the spring. J. Atmos. Sci., 42, 17111732.

    • Search Google Scholar
    • Export Citation
  • Caruso, J. M., and J. M. Davies, 2005: Tornadoes in nonmesocyclone environments with pre-existing vertical vorticity along convergence boundaries. Electron. J. Oper. Meteor., Paper 2005-EJ4. [Available online at www.nwas.org/ej/pdf/2005-EJ4.pdf.]

    • Search Google Scholar
    • Export Citation
  • Chisholm, A. J., and J. H. Renick, 1972: The kinematics of multicell and supercell Alberta hailstorms. Alberta Hail Studies, Rep. 72-2, Research Council of Alberta, 7 pp.

    • Search Google Scholar
    • Export Citation
  • Coniglio, M. C., D. J. Stensrud, and L. J. Wicker, 2006: Effects of upper-level shear on the structure and maintenance of strong quasi-linear mesoscale convective systems. J. Atmos. Sci., 63, 12311252.

    • Search Google Scholar
    • Export Citation
  • Deardorff, J. W., 1972: Numerical investigation of the neutral and unstable planetary boundary layers. J. Atmos. Sci., 29, 91115.

  • Doswell, C. A., III, A. R. Moller, and R. Przybylinski, 1990: A unified set of conceptual models for variations on the supercell theme. Preprints, 16th Conf. on Severe Local Storms, Kananaskis Park, AB, Canada, Amer. Meteor. Soc., 40–45.

    • Search Google Scholar
    • Export Citation
  • Fierro, A. O., M. S. Gilmore, E. R. Mansell, L. J. Wicker, and J. M. Straka, 2006: Electrification and lightning in an idealized boundary-crossing supercell simulation of 2 June 1995. Mon. Wea. Rev., 134, 31493172.

    • Search Google Scholar
    • Export Citation
  • Gilmore, M. S., and L. J. Wicker, 2002: Influences of the local environment on supercell cloud-to-ground lightning, radar characteristics, and severe weather on 2 June 1995. Mon. Wea. Rev., 130, 23492372.

    • Search Google Scholar
    • Export Citation
  • Gilmore, M. S., J. M. Straka, and E. N. Rasmussen, 2004: Precipitation evolution sensitivity in simulated deep convective storms: Comparisons between liquid-only and simple ice and liquid phase microphysics. Mon. Wea. Rev., 132, 18971916.

    • Search Google Scholar
    • Export Citation
  • Godunov, S. K., 1959: Finite-difference method for the numerical computations of equations of gas dynamics. Mat. Sb. (N. S.), 7, 271290.

    • Search Google Scholar
    • Export Citation
  • Hemler, R. S., F. B. Lipps, and B. B. Ross, 1991: A simulation of a squall line using a nonhydrostatic cloud model with 5-km horizontal grid. Mon. Wea. Rev., 119, 30123033.

    • Search Google Scholar
    • Export Citation
  • Houston, A. L., 2004: The role of preexisting airmass boundaries in the maintenance and rotation of deep convection in a high-CAPE, low-shear environment. Ph.D. dissertation, Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, IL, 275 pp.

    • Search Google Scholar
    • Export Citation
  • Houston, A. L., and D. Niyogi, 2007: The sensitivity of convective initiation to the lapse rate of the active cloud-bearing layer. Mon. Wea. Rev., 135, 30133032.

    • Search Google Scholar
    • Export Citation
  • Houston, A. L., and R. B. Wilhelmson, 2007a: Observational analysis of the 27 May 1997 central Texas tornadic event. Part I: Prestorm environment and storm maintenance/propagation. Mon. Wea. Rev., 135, 701726.

    • Search Google Scholar
    • Export Citation
  • Houston, A. L., and R. B. Wilhelmson, 2007b: Observational analysis of the 27 May 1997 central Texas tornadic event. Part II: Tornadoes. Mon. Wea. Rev., 135, 727735.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., and R. B. Wilhelmson, 1978: The simulation of three-dimensional convective storm dynamics. J. Atmos. Sci., 35, 10701096.

    • Search Google Scholar
    • Export Citation
  • Koch, S. E., and J. McCarthy, 1982: The evolution of an Oklahoma dryline. Part II: Boundary-layer forcing of mesoconvective systems. J. Atmos. Sci., 39, 237257.

    • Search Google Scholar
    • Export Citation
  • Koch, S. E., and W. L. Clark, 1999: A nonclassical cold front observed during COPS-91: Frontal structure and the process of severe storm initiation. J. Atmos. Sci., 56, 28622890.

    • Search Google Scholar
    • Export Citation
  • Lee, B. D., and R. B. Wilhelmson, 1997a: The numerical simulation of nonsupercell tornadogenesis. Part I: Initiation and evolution of pretornadic misocyclone circulations along a dry outflow boundary. J. Atmos. Sci., 54, 3260.

    • Search Google Scholar
    • Export Citation
  • Lee, B. D., and R. B. Wilhelmson, 1997b: The numerical simulation of nonsupercell tornadogenesis. Part II: Evolution of a family of tornadoes along a weak outflow boundary. J. Atmos. Sci., 54, 23872415.

    • Search Google Scholar
    • Export Citation
  • Lee, B. D., and R. B. Wilhelmson, 2000: The numerical simulation of nonsupercell tornadogenesis. Part III: Parameter tests investigating the role of CAPE, vortex sheet strength, and boundary layer vertical shear. J. Atmos. Sci., 57, 22462261.

    • Search Google Scholar
    • Export Citation
  • Leonard, B. P., 1991: The ULTIMATE conservative difference scheme applied to unsteady one-dimensional advection. Comput. Methods Appl. Mech. Eng., 88, 1774.

    • Search Google Scholar
    • Export Citation
  • Maddox, R. A., L. R. Hoxit, and C. F. Chappell, 1980: A study of tornadic thunderstorm interactions with thermal boundaries. Mon. Wea. Rev., 108, 322336.

    • Search Google Scholar
    • Export Citation
  • Magsig, M. A., D. W. Burgess, and R. R. Lee, 1998: Multiple boundary evolution and tornadogenesis associated with the Jarrell, Texas, events. Preprints, 19th Conf. on Severe Local Storms, Minneapolis, MN, Amer. Meteor. Soc., 186–189.

    • Search Google Scholar
    • Export Citation
  • Markowski, P. M., E. N. Rasmussen, and J. M. Straka, 1998: The occurrence of tornadoes in supercells interacting with boundaries during VORTEX-95. Wea. Forecasting, 13, 852859.

    • Search Google Scholar
    • Export Citation
  • Moller, A. R., 1982: A record-breaking severe thunderstorm event in North Texas. Preprints, Ninth Conf. on Weather Forecasting and Analysis, Seattle, WA, Amer. Meteor. Soc., 396–401.

    • Search Google Scholar
    • Export Citation
  • Moller, A. R., C. A. Doswell III, and R. Przybylinski, 1990: High-precipitation supercells: A conceptual model and documentation. Preprints, 16th Conf. on Severe Local Storms, Kananaskis Park, AB, Canada, Amer. Meteor. Soc., 52–57.

    • Search Google Scholar
    • Export Citation
  • Neiman, P. J., and R. M. Wakimoto, 1999: The interaction of a Pacific cold front with shallow air masses east of the Rocky Mountains. Mon. Wea. Rev., 127, 21022127.

    • Search Google Scholar
    • Export Citation
  • Newton, C. W., 1963: Dynamics of Severe Convective Storms. Meteor. Mongr., No. 27, Amer. Meteor. Soc., 33–58.

  • Parker, M. D., 2007: Simulated convective lines with parallel stratiform precipitation. Part I: An archetype for convection in along-line shear. J. Atmos. Sci., 64, 267288.

    • Search Google Scholar
    • Export Citation
  • Parsons, D. B., M. A. Shapiro, R. M. Hardesty, R. J. Zamora, and J. M. Intrieri, 1991: The finescale structure of a west Texas dryline. Mon. Wea. Rev., 119, 12421258.

    • Search Google Scholar
    • Export Citation
  • Parsons, D. B., M. A. Shapiro, and E. Miller, 2000: A mesoscale structure of a nocturnal dryline and a frontal-dryline merger. Mon. Wea. Rev., 128, 38243838.

    • Search Google Scholar
    • Export Citation
  • Purdom, J. F. W., 1976: Some uses of high-resolution GOES imagery in the mesoscale forecasting of convection and its behavior. Mon. Wea. Rev., 104, 14741483.

    • Search Google Scholar
    • Export Citation
  • Purdom, J. F. W., 1993: Satellite observations of tornadic thunderstorms. The Tornado: Its Structure, Dynamics, Prediction, and Hazards, Geophys. Monogr., Vol. 79, Amer. Geophys. Union, 265–274.

    • Search Google Scholar
    • Export Citation
  • Rasmussen, E. N., S. Richardson, J. M. Straka, P. M. Markowski, and D. O. Blanchard, 2000: The association of significant tornadoes with a baroclinic boundary on 2 June 1995. Mon. Wea. Rev., 128, 174191.

    • Search Google Scholar
    • Export Citation
  • Roberts, R. D., and J. W. Wilson, 1995: The genesis of three nonsupercell tornadoes observed with dual-Doppler radar. Mon. Wea. Rev., 123, 34083436.

    • Search Google Scholar
    • Export Citation
  • Ross, B. B., 1987: The role of low-level convergence and latent heating in a simulation of observed squall line formation. Mon. Wea. Rev., 115, 22982321.

    • Search Google Scholar
    • Export Citation
  • Simpson, J., B. R. Morton, M. C. McCumber, and R. S. Penc, 1986: Observations and mechanisms of GATE waterspouts. J. Atmos. Sci., 43, 753782.

    • Search Google Scholar
    • Export Citation
  • Skamarock, W. C., and J. B. Klemp, 1992: The stability of time-split numerical methods for the hydrostatic and the nonhydrostatic elastic equations. Mon. Wea. Rev., 120, 21092127.

    • Search Google Scholar
    • Export Citation
  • Smith, P. L. J., C. G. Myers, and H. D. Orville, 1975: Radar reflectivity factor calculations in numerical cloud models using bulk parameterization of precipitation. J. Appl. Meteor., 14, 11561165.

    • Search Google Scholar
    • Export Citation
  • Thuburn, J., 1995: Dissipation and cascades to small scales in numerical models using a shape-preserving advection scheme. Mon. Wea. Rev., 123, 18881903.

    • Search Google Scholar
    • Export Citation
  • van Leer, B., 1974: Towards the ultimate conservative difference scheme. II: Monotonicity and conservation combined in a second order scheme. J. Comput. Phys., 14, 361370.

    • Search Google Scholar
    • Export Citation
  • Wade, C. G., and G. B. Foote, 1982: The 22 July 1976 case study: Low-level airflow and mesoscale influences. Hailstorms of the Central High Plains, C. A. Knight and P. Squires, Eds., Colorado Associated University Press, 115–130.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., and J. W. Wilson, 1989: Non-supercell tornadoes. Mon. Wea. Rev., 117, 11131140.

  • Wakimoto, R. M., C. Liu, and H. Cai, 1998: The Garden City, Kansas, storm during VORTEX-95. Part I: Overview of storms life cycle and mesocyclogenesis. Mon. Wea. Rev., 126, 372392.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., H. V. Murphey, E. V. Browell, and S. Ismail, 2006: The “triple point” on 24 May 2002 during IHOP. Part I: Airborne Doppler and LASE analysis of the frontal boundaries and convection initiation. Mon. Wea. Rev., 134, 231250.

    • Search Google Scholar
    • Export Citation
  • Weaver, J. F., 1979: Storm motion as related to boundary-layer convergence. Mon. Wea. Rev., 107, 612619.

  • Weaver, J. F., and S. P. Nelson, 1982: Multiscale aspects of thunderstorm gust fronts and their effects on subsequent storm development. Mon. Wea. Rev., 110, 707718.

    • Search Google Scholar
    • Export Citation
  • Weaver, J. F., J. F. W. Purdom, and E. J. Szoke, 1994: Some mesoscale aspects of the 6 June 1990 Limon, Colorado, tornado case. Wea. Forecasting, 9, 4561.

    • Search Google Scholar
    • Export Citation
  • Weckwerth, T. M., and D. B. Parsons, 2006: A review of convection initiation and motivation for IHOP_2002. Mon. Wea. Rev., 134, 522.

  • Wicker, L. J., and R. B. Wilhelmson, 1995: Simulation and analysis of tornado development and decay within a three-dimensional supercell thunderstorm. J. Atmos. Sci., 52, 26752703.

    • Search Google Scholar
    • Export Citation
  • Wicker, L. J., and W. C. Skamarock, 1998: A time-splitting scheme for the elastic equations incorporating second-order Runge–Kutta time differencing. Mon. Wea. Rev., 126, 19921999.

    • Search Google Scholar
    • Export Citation
  • Wicker, L. J., and W. C. Skamarock, 2002: Time-splitting methods for elastic models using forward time schemes. Mon. Wea. Rev., 130, 20882097.

    • Search Google Scholar
    • Export Citation
  • Wilczak, J. M., T. W. Christian, D. E. Wolfe, R. J. Zamora, and B. Stankov, 1992: Observations of a Colorado tornado. Part I: Mesoscale environment and tornadogenesis. Mon. Wea. Rev., 120, 497520.

    • Search Google Scholar
    • Export Citation
  • Wilhelmson, R. B., and C.-S. Chen, 1982: A simulation of the development of successive cells along a cold outflow boundary. J. Atmos. Sci., 39, 14661483.

    • Search Google Scholar
    • Export Citation
  • Wilson, J. W., and W. E. Schreiber, 1986: Initiation of convective storms at radar-observed boundary-layer convergence lines. Mon. Wea. Rev., 114, 25162536.

    • Search Google Scholar
    • Export Citation
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The Impact of Airmass Boundaries on the Propagation of Deep Convection: A Modeling-Based Study in a High-CAPE, Low-Shear Environment

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  • 1 Department of Earth and Atmospheric Sciences, University of Nebraska—Lincoln, Lincoln, Nebraska
  • | 2 National Center for Supercomputing Applications, and Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois
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Abstract

A suite of experiments conducted using a cloud-resolving model is examined to assess the role that preexisting airmass boundaries can play in regulating storm propagation. The 27 May 1997 central Texas tornadic event is used to guide these experiments. The environment of this event was characterized by multiple preexisting airmass boundaries, large CAPE, and weak vertical shear.

Only the experiments with preexisting airmass boundaries produce back-building storm propagation (storm motion in opposition to the mean wind). When both the cold front and dryline are present, storm maintenance occurs through the quasi-continuous maintenance of a set of long-lived updrafts and not through discrete updraft redevelopment. Since the cold front is not required for back building, it is clear that back building in this environment does not require quasi-continuous updraft maintenance. The back-building storm simulated with both the cold front and dryline is found to be anchored to the boundary zipper (the intersection of the cold front and dryline). However, multiple preexisting airmass boundaries are not required for back building since experiments with only a dryline also support back building. A conceptual model of back building and boundary zippering is developed that highlights the important role that preexisting boundaries can play in back-building propagation.

Corresponding author address: Dr. Adam L. Houston, Department of Earth and Atmospheric Sciences, University of Nebraska—Lincoln, 214 Bessey Hall, Lincoln, NE 68588. E-mail: ahouston2@unl.edu

Abstract

A suite of experiments conducted using a cloud-resolving model is examined to assess the role that preexisting airmass boundaries can play in regulating storm propagation. The 27 May 1997 central Texas tornadic event is used to guide these experiments. The environment of this event was characterized by multiple preexisting airmass boundaries, large CAPE, and weak vertical shear.

Only the experiments with preexisting airmass boundaries produce back-building storm propagation (storm motion in opposition to the mean wind). When both the cold front and dryline are present, storm maintenance occurs through the quasi-continuous maintenance of a set of long-lived updrafts and not through discrete updraft redevelopment. Since the cold front is not required for back building, it is clear that back building in this environment does not require quasi-continuous updraft maintenance. The back-building storm simulated with both the cold front and dryline is found to be anchored to the boundary zipper (the intersection of the cold front and dryline). However, multiple preexisting airmass boundaries are not required for back building since experiments with only a dryline also support back building. A conceptual model of back building and boundary zippering is developed that highlights the important role that preexisting boundaries can play in back-building propagation.

Corresponding author address: Dr. Adam L. Houston, Department of Earth and Atmospheric Sciences, University of Nebraska—Lincoln, 214 Bessey Hall, Lincoln, NE 68588. E-mail: ahouston2@unl.edu
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