• Adams-Selin, R. D., 2020a: Impact of convectively generated low-frequency gravity waves on evolution of mesoscale convective systems. J. Atmos. Sci., 77, 34413460, https://doi.org/10.1175/JAS-D-19-0250.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Adams-Selin, R. D., 2020b: Sensitivity of MCS low-frequency gravity waves to microphysical variations. J. Atmos. Sci., 77, 34613477, https://doi.org/10.1175/JAS-D-19-0347.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Adams-Selin, R. D., and R. H. Johnson, 2013: Examination of gravity waves associated with the 13 March 2003 bow echo. Mon. Wea. Rev., 141, 37353756, https://doi.org/10.1175/MWR-D-12-00343.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bryan, G. H., and H. Morrison, 2012: Sensitivity of a simulated squall line to horizontal resolution and parameterization of microphysics. Mon. Wea. Rev., 140, 202225, https://doi.org/10.1175/MWR-D-11-00046.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bryan, G. H., R. Rotunno, and J. M. Fritsch, 2007: Roll circulations in the convective region of a simulated squall line. J. Atmos. Sci., 64, 12491266, https://doi.org/10.1175/JAS3899.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Coleman, T. A., and K. R. Knupp, 2011: Radiometer and profiler analysis of the effects of a bore and a solitary wave on the stability of the nocturnal boundary layer. Mon. Wea. Rev., 139, 211223, https://doi.org/10.1175/2010MWR3376.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fovell, R. G., 2002: Upstream influence of numerically simulated squall-line storms. Quart. J. Roy. Meteor. Soc., 128, 893912, https://doi.org/10.1256/0035900021643737.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fovell, R. G., G. L. Mullendore, and S.-H. Kim, 2006: Discrete propagation in numerically simulated nocturnal squall lines. Mon. Wea. Rev., 134, 37353752, https://doi.org/10.1175/MWR3268.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fritsch, J., and G. Forbes, 2001: Mesoscale convective systems. Severe Convective Storms, Springer, 323–357.

    • Crossref
    • Export Citation
  • Fritsch, J., R. Kane, and C. Chelius, 1986: The contribution of mesoscale convective weather systems to the warm-season precipitation in the United States. J. Appl. Meteor. Climatol., 25, 13331345, https://doi.org/10.1175/1520-0450(1986)025<1333:TCOMCW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gallus, W. A., and R. H. Johnson, 1991: Heat and moisture budgets of an intense midlatitude squall line. J. Atmos. Sci., 48, 122146, https://doi.org/10.1175/1520-0469(1991)048<0122:HAMBOA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Geerts, B., and Coauthors, 2017: The 2015 Plains Elevated Convection at Night field project. Bull. Amer. Meteor. Soc., 98, 767786, https://doi.org/10.1175/BAMS-D-15-00257.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grasmick, C., B. Geerts, D. D. Turner, Z. Wang, and T. Weckwerth, 2018: The relation between nocturnal MCS evolution and its outflow boundaries in the stable boundary layer: An observational study of the 15 July 2015 MCS in PECAN. Mon. Wea. Rev., 146, 32033226, https://doi.org/10.1175/MWR-D-18-0169.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Haghi, K. R., and Coauthors, 2019: Bore-ing into nocturnal convection. Bull. Amer. Meteor. Soc., 100, 11031121, https://doi.org/10.1175/BAMS-D-17-0250.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hitchcock, S. M., R. S. Schumacher, G. R. Herman, M. C. Coniglio, M. D. Parker, and C. L. Ziegler, 2019: Evolution of pre-and postconvective environmental profiles from mesoscale convective systems during PECAN. Mon. Wea. Rev., 147, 23292354, https://doi.org/10.1175/MWR-D-18-0231.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Houze, R. A., Jr., 2004: Mesoscale convective systems. Rev. Geophys., 42, RG4003, https://doi.org/10.1029/2004RG000150.

  • Hubbert, J. C., J. W. Wilson, T. M. Weckwerth, S. M. Ellis, M. Dixon, and E. Loew, 2018: S-Pol’s polarimetric data reveal detailed storm features (and insect behavior). Bull. Amer. Meteor. Soc., 99, 20452060, https://doi.org/10.1175/BAMS-D-17-0317.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knupp, K., 2006: Observational analysis of a gust front to bore to solitary wave transition within an evolving nocturnal boundary layer. J. Atmos. Sci., 63, 20162035, https://doi.org/10.1175/JAS3731.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Koch, S. E., P. B. Dorian, R. Ferrare, S. Melfi, W. C. Skillman, and D. Whiteman, 1991: Structure of an internal bore and dissipating gravity current as revealed by Raman lidar. Mon. Wea. Rev., 119, 857887, https://doi.org/10.1175/1520-0493(1991)119<0857:SOAIBA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lane, T. P., and M. J. Reeder, 2001: Convectively generated gravity waves and their effect on the cloud environment. J. Atmos. Sci., 58, 24272440, https://doi.org/10.1175/1520-0469(2001)058<2427:CGGWAT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lane, T. P., and F. Zhang, 2011: Coupling between gravity waves and tropical convection at mesoscales. J. Atmos. Sci., 68, 25822598, https://doi.org/10.1175/2011JAS3577.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mapes, B. E., 1993: Gregarious tropical convection. J. Atmos. Sci., 50, 20262037, https://doi.org/10.1175/1520-0469(1993)050<2026:GTC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Markowski, P., and Y. Richardson, 2011: Mesoscale Meteorology in Midlatitudes. Vol. 2. John Wiley and Sons, 253–258.

    • Crossref
    • Export Citation
  • McAnelly, R. L., J. E. Nachamkin, W. R. Cotton, and M. E. Nicholls, 1997: Upscale evolution of MCSs: Doppler radar analysis and analytical investigation. Mon. Wea. Rev., 125, 10831110, https://doi.org/10.1175/1520-0493(1997)125<1083:UEOMDR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Morrison, H., G. Thompson, and V. Tatarskii, 2009: Impact of cloud microphysics on the development of trailing stratiform precipitation in a simulated squall line: Comparison of one- and two-moment schemes. Mon. Wea. Rev., 137, 9911007, https://doi.org/10.1175/2008MWR2556.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Naylor, J., and M. S. Gilmore, 2012: Convective initiation in an idealized cloud model using an updraft nudging technique. Mon. Wea. Rev., 140, 36993705, https://doi.org/10.1175/MWR-D-12-00163.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nicholls, M. E., R. A. Pielke, and W. R. Cotton, 1991: Thermally forced gravity waves in an atmosphere at rest. J. Atmos. Sci., 48, 18691884, https://doi.org/10.1175/1520-0469(1991)048<1869:TFGWIA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Parker, M. D., 2008: Response of simulated squall lines to low-level cooling. J. Atmos. Sci., 65, 13231341, https://doi.org/10.1175/2007JAS2507.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Parker, M. D., 2021: Self-organization and maintenance of simulated nocturnal convective systems from PECAN. Mon. Wea. Rev., 149, 9991022, https://doi.org/10.1175/MWR-D-20-0263.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Parker, M. D., and R. H. Johnson, 2004: Structures and dynamics of quasi-2D mesoscale convective systems. J. Atmos. Sci., 61, 545567, https://doi.org/10.1175/1520-0469(2004)061<0545:SADOQM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Parsons, D. B., K. R. Haghi, K. T. Halbert, B. Elmer, and J. Wang, 2019: The potential role of atmospheric bores and gravity waves in the initiation and maintenance of nocturnal convection over the Southern Great Plains. J. Atmos. Sci., 76, 4368, https://doi.org/10.1175/JAS-D-17-0172.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Peters, J. M., and R. S. Schumacher, 2016: Dynamics governing a simulated mesoscale convective system with a training convective line. J. Atmos. Sci., 73, 26432664, https://doi.org/10.1175/JAS-D-15-0199.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci., 45, 463485, https://doi.org/10.1175/1520-0469(1988)045<0463:ATFSLL>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schmidt, J. M., and W. R. Cotton, 1990: Interactions between upper and lower tropospheric gravity waves on squall line structure and maintenance. J. Atmos. Sci., 47, 12051222, https://doi.org/10.1175/1520-0469(1990)047<1205:IBUALT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schumacher, R. S., 2009: Mechanisms for quasi-stationary behavior in simulated heavy-rain-producing convective systems. J. Atmos. Sci., 66, 15431568, https://doi.org/10.1175/2008JAS2856.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schumacher, R. S., and R. H. Johnson, 2005: Organization and environmental properties of extreme-rain-producing mesoscale convective systems. Mon. Wea. Rev., 133, 961976, https://doi.org/10.1175/MWR2899.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Skamarock, W. C., 2004: Evaluating mesoscale NWP models using kinetic energy spectra. Mon. Wea. Rev., 132, 30193032, https://doi.org/10.1175/MWR2830.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Su, T., and G. Zhai, 2017: The role of convectively generated gravity waves on convective initiation: A case study. Mon. Wea. Rev., 145, 335359, https://doi.org/10.1175/MWR-D-16-0196.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trapp, R. J., and J. M. Woznicki, 2017: Convectively induced stabilizations and subsequent recovery with supercell thunderstorms during the Mesoscale Predictability Experiment (MPEX). Mon. Wea. Rev., 145, 17391754, https://doi.org/10.1175/MWR-D-16-0266.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., and J. B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504520, https://doi.org/10.1175/1520-0493(1982)110<0504:TDONSC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., W. C. Skamarock, and J. B. Klemp, 1997: The resolution dependence of explicitly modeled convective systems. Mon. Wea. Rev., 125, 527548, https://doi.org/10.1175/1520-0493(1997)125<0527:TRDOEM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilks, D. S., 2011: Statistical Methods in the Atmospheric Sciences. Academic Press, 676 pp.

  • Wilson, J., S. Trier, D. Reif, R. Roberts, and T. Weckwerth, 2018: Nocturnal elevated convection initiation of the PECAN 4 July hailstorm. Mon. Wea. Rev., 146, 243262, https://doi.org/10.1175/MWR-D-17-0176.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, S., D. B. Parsons, and Y. Wang, 2020: Wave disturbances and their role in the maintenance, structure, and evolution of a mesoscale convection system. J. Atmos. Sci., 77, 5177, https://doi.org/10.1175/JAS-D-18-0348.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
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Response of MCS Low-Frequency Gravity Waves to Vertical Wind Shear and Nocturnal Thermodynamic Environments

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  • 1 aDepartment of Atmospheric Science, Colorado State University, Fort Collins, Colorado
  • | 2 bAtmospheric and Environmental Research, Inc., Lexington, Massachusetts
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Abstract

This study investigates the sensitivities of mesoscale convective system (MCS) low-frequency gravity waves to changes in the vertical wind and thermodynamic profile through idealized cloud model simulations, highlighting how internal MCS processes impact low-frequency gravity wave generation, propagation, and environmental influence. Spectral analysis is performed on the rates of latent heat release, updraft velocity, and deep-tropospheric descent ahead of the convection as a signal for vertical wavenumber n=1 wave passage. Results show that perturbations in midlevel descent up to 100 km ahead of the MCS occur at the same frequency as n=1 gravity wave generation prompted by fluctuations in latent heat release due to the cellular variations of the MCS updrafts. Within a nocturnal environment, the frequency of the cellularity of the updrafts increases, subsequently increasing the frequency of n=1 wave generation. In an environment with low-level unidirectional shear, results indicate that n=2 wave generation mechanisms and environmental influence are similar among the simulated daytime and nocturnal MCSs. When deep vertical wind shear is incorporated, many of the low-frequency waves are strong enough to support cloud development ahead of the MCS as well as sustain and support convection.

Groff’s current affiliation: CPP Wind Engineering and Air Quality Consultants, Windsor, Colorado.

© 2021 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: Faith P. Groff, Fgroff@cppwind.com

Abstract

This study investigates the sensitivities of mesoscale convective system (MCS) low-frequency gravity waves to changes in the vertical wind and thermodynamic profile through idealized cloud model simulations, highlighting how internal MCS processes impact low-frequency gravity wave generation, propagation, and environmental influence. Spectral analysis is performed on the rates of latent heat release, updraft velocity, and deep-tropospheric descent ahead of the convection as a signal for vertical wavenumber n=1 wave passage. Results show that perturbations in midlevel descent up to 100 km ahead of the MCS occur at the same frequency as n=1 gravity wave generation prompted by fluctuations in latent heat release due to the cellular variations of the MCS updrafts. Within a nocturnal environment, the frequency of the cellularity of the updrafts increases, subsequently increasing the frequency of n=1 wave generation. In an environment with low-level unidirectional shear, results indicate that n=2 wave generation mechanisms and environmental influence are similar among the simulated daytime and nocturnal MCSs. When deep vertical wind shear is incorporated, many of the low-frequency waves are strong enough to support cloud development ahead of the MCS as well as sustain and support convection.

Groff’s current affiliation: CPP Wind Engineering and Air Quality Consultants, Windsor, Colorado.

© 2021 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: Faith P. Groff, Fgroff@cppwind.com
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