Editorial Type:
Article
Article Type:
Research Article

Microphysical and Thermodynamic Structure and Evolution of the Trailing Stratiform Regions of Mesoscale Convective Systems during BAMEX. Part I: Observations

Andrea M. Smith Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Andrea M. Smith in
Current site
Google Scholar
PubMed Close
,
Greg M. McFarquhar Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Greg M. McFarquhar in
Current site
Google Scholar
PubMed Close
,
Robert M. Rauber Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Robert M. Rauber in
Current site
Google Scholar
PubMed Close
,
Joseph A. Grim Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Joseph A. Grim in
Current site
Google Scholar
PubMed Close
,
Michael S. Timlin Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Michael S. Timlin in
Current site
Google Scholar
PubMed Close
,
Brian F. Jewett Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois

Search for other papers by Brian F. Jewett in
Current site
Google Scholar
PubMed Close
, and
David P. Jorgensen NOAA/National Severe Storms Laboratory, Norman, Oklahoma

Search for other papers by David P. Jorgensen in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Apr 2009
DOI:
https://doi.org/10.1175/2008MWR2504.1
Page(s):
1165–1185
Restricted access

Abstract

This study used airborne and ground-based radar and optical array probe data from the spiral descent flight patterns and horizontal flight legs of the NOAA P-3 aircraft in the trailing stratiform regions (TSRs) of mesoscale convective systems (MCSs) observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) to characterize microphysical and thermodynamic variations within the TSRs in the context of the following features: the transition zone, the notch region, the enhanced stratiform rain region, the rear anvil region, the front-to-rear flow, the rear-to-front flow, and the rear inflow jet axis. One spiral from the notch region, nine from the enhanced stratiform rain region, and two from the rear anvil region were analyzed along with numerous horizontal flight legs that traversed these zones. The spiral performed in the notch region on 29 June occurred early in the MCS life cycle and exhibited subsaturated conditions throughout its depth. The nine spirals performed within the enhanced stratiform rain region exhibited saturated conditions with respect to ice above and within the melting layer and subsaturated conditions below the melting layer. Spirals performed in the rear anvil region showed saturation until the base of the anvil, near −1°C, and subsaturation below. These data, together with analyses of total number concentration and the slope to gamma fits to size distributions, revealed that sublimation above the melting layer occurs early in the MCS life cycle but then reduces in importance as the environment behind the convective line is moistened from the top down. Evaporation below the melting layer was insufficient to attain saturation below the melting layer at any time or location within the MCS TSRs. Relative humidity was found to have a strong correlation to the component of wind parallel to the storm motion, especially within air flowing from front to rear.

* Current affiliation: National Center for Atmospheric Research, Boulder, Colorado.

Corresponding author address: Andrea Smith, Dept. of Atmospheric Sciences, University of Illinois at Urbana–Champaign, 105 S. Gregory St., Urbana, IL 61801. Email: asmith5@atmos.uiuc.edu

Abstract

This study used airborne and ground-based radar and optical array probe data from the spiral descent flight patterns and horizontal flight legs of the NOAA P-3 aircraft in the trailing stratiform regions (TSRs) of mesoscale convective systems (MCSs) observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) to characterize microphysical and thermodynamic variations within the TSRs in the context of the following features: the transition zone, the notch region, the enhanced stratiform rain region, the rear anvil region, the front-to-rear flow, the rear-to-front flow, and the rear inflow jet axis. One spiral from the notch region, nine from the enhanced stratiform rain region, and two from the rear anvil region were analyzed along with numerous horizontal flight legs that traversed these zones. The spiral performed in the notch region on 29 June occurred early in the MCS life cycle and exhibited subsaturated conditions throughout its depth. The nine spirals performed within the enhanced stratiform rain region exhibited saturated conditions with respect to ice above and within the melting layer and subsaturated conditions below the melting layer. Spirals performed in the rear anvil region showed saturation until the base of the anvil, near −1°C, and subsaturation below. These data, together with analyses of total number concentration and the slope to gamma fits to size distributions, revealed that sublimation above the melting layer occurs early in the MCS life cycle but then reduces in importance as the environment behind the convective line is moistened from the top down. Evaporation below the melting layer was insufficient to attain saturation below the melting layer at any time or location within the MCS TSRs. Relative humidity was found to have a strong correlation to the component of wind parallel to the storm motion, especially within air flowing from front to rear.

* Current affiliation: National Center for Atmospheric Research, Boulder, Colorado.

Corresponding author address: Andrea Smith, Dept. of Atmospheric Sciences, University of Illinois at Urbana–Champaign, 105 S. Gregory St., Urbana, IL 61801. Email: asmith5@atmos.uiuc.edu

Save
Cover Monthly Weather Review
Monthly Weather Review

  • Biggerstaff, M. I., and R. A. Houze Jr., 1991: Kinematic and precipitation structure of the 10–11 June 1985 squall line. Mon. Wea. Rev., 119 , 3034–3065.

    • Search Google Scholar
    • Export Citation

  • Biggerstaff, M. I., and R. A. Houze Jr., 1993: Kinematics and microphysics of the transition zone of the 10–11 June 1985 squall line. J. Atmos. Sci., 50 , 3091–3110.

    • Search Google Scholar
    • Export Citation

  • Braun, S. A., and R. A. Houze Jr., 1994: The transition zone and secondary maximum of radar reflectivity behind a midlatitude squall line: Results retrieved from Doppler radar data. J. Atmos. Sci., 51 , 2733–2755.

    • Search Google Scholar
    • Export Citation

  • Braun, S. A., and R. A. Houze, 1997: The evolution of the 10–11 June 1985 PRE-STORM squall line: Initiation, development of rear inflow, and dissipation. Mon. Wea. Rev., 125 , 478–504.

    • Search Google Scholar
    • Export Citation

  • Caniaux, G., J-P. Lafore, and J-L. Redelsperger, 1995: A numerical study of the stratiform region of a fast-moving squall line. Part II: Relationship between mass, pressure, and momentum fields. J. Atmos. Sci., 52 , 331–352.

    • Search Google Scholar
    • Export Citation

  • Churchill, D. D., and R. A. Houze, 1984: Development and structure of winter monsoon cloud clusters on 10 December 1978. J. Atmos. Sci., 41 , 933–960.

    • Search Google Scholar
    • Export Citation

  • Davis, C., and Coauthors, 2004: The Bow Echo and MCV Experiment: Observations and opportunities. Bull. Amer. Meteor. Soc., 85 , 1075–1093.

    • Search Google Scholar
    • Export Citation

  • Eastin, M. D., P. G. Black, and W. M. Gray, 2002: Flight-level thermodynamic instrument wetting errors in hurricanes. Part I: Observations. Mon. Wea. Rev., 130 , 825–841.

    • Search Google Scholar
    • Export Citation

  • Fovell, R. G., and Y. Ogura, 1989: Effect of vertical wind shear on numerically simulated multicell storm structure. J. Atmos. Sci., 46 , 3144–3176.

    • Search Google Scholar
    • Export Citation

  • Grim, J. A., G. M. McFarquhar, R. M. Rauber, A. M. Smith, and B. F. Jewett, 2009a: Microphysical and thermodynamic structure and evolution of the trailing stratiform regions of mesoscale convective systems during BAMEX. Part II: Column model simulations. Mon. Wea. Rev., 137 , 1186–1205.

    • Search Google Scholar
    • Export Citation

  • Grim, J. A., R. M. Rauber, G. M. McFarquhar, B. F. Jewett, and D. P. Jorgensen, 2009b: Development and forcing of the rear inflow jet in a rapidly developing and decaying squall line during BAMEX. Mon. Wea. Rev., 137 , 1206–1229.

    • Search Google Scholar
    • Export Citation

  • Hallett, J., 2003: Measurement in the atmosphere. Handbook of Weather, Climate and Water: Dynamics, Climate, Physical Meteorology, Weather Systems and Measurements, T. D. Potter and B. R. Colman, Eds., John Wiley and Sons, 711–720.

    • Search Google Scholar
    • Export Citation

  • Houze, R. A., M. Biggerstaff, S. Rutledge, and B. Smull, 1989: Interpretation of Doppler weather radar displays of midlatitude mesoscale convective systems. Bull. Amer. Meteor. Soc., 70 , 608–619.

    • Search Google Scholar
    • Export Citation

  • Houze, R. A., B. F. Smull, and P. Dodge, 1990: Mesoscale organization of springtime rainstorms in Oklahoma. Mon. Wea. Rev., 118 , 613–654.

    • Search Google Scholar
    • Export Citation

  • Jorgensen, D. F., 1984: Mesoscale and convective-scale characteristics of mature hurricanes. Part I: General observations by research aircraft. J. Atmos. Sci., 41 , 1268–1286.

    • Search Google Scholar
    • Export Citation

  • Jorgensen, D. P., T. Matejka, and J. D. DuGranrut, 1996: Multi-beam techniques for deriving wind fields from airborne Doppler radars. J. Meteor. Atmos. Phys., 59 , 83–104.

    • Search Google Scholar
    • Export Citation

  • Knollenberg, R. G., 1981: Techniques for probing cloud microstructure. Clouds, Their Formation, Optical Properties and Effects, P. V. Hobbs and A. Deepak, Eds., Academic Press, 15–92.

    • Search Google Scholar
    • Export Citation

  • McFarquhar, G. M., M. S. Timlin, R. M. Rauber, B. F. Jewett, J. A. Grim, and D. P. Jorgensen, 2007: Vertical variability of cloud hydrometeors in the stratiform region of mesoscale convective systems and bow echoes. Mon. Wea. Rev., 135 , 3405–3428. Corrigendum. 137, 1493.

    • Search Google Scholar
    • Export Citation

  • Nicholls, M. E., 1987: A comparison of the results of a two-dimensional numerical simulation of a tropical squall line with observations. Mon. Wea. Rev., 115 , 3055–3077.

    • Search Google Scholar
    • Export Citation

  • Oye, R., C. Mueller, and S. Smith, 1995: Software for radar translation, visualization, editing, and interpolation. Preprints, 27th Conf. on Radar Meteorology, Vail, CO, Amer. Meteor. Soc., 359–361.

    • Search Google Scholar
    • Export Citation

  • Parker, M. D., and R. H. Johnson, 2000: Organizational modes of midlatitude mesoscale convective systems. Mon. Wea. Rev., 128 , 3413–3436.

    • Search Google Scholar
    • Export Citation

  • Przybylinski, R. W., 1995: The bow echo: Observations, numerical simulations, and severe weather detection methods. Wea. Forecasting, 10 , 203–218.

    • Search Google Scholar
    • Export Citation

  • Rutledge, S. A., and R. A. Houze Jr., 1987: A diagnostic modeling study of the trailing stratiform region of a midlatitude squall line. J. Atmos. Sci., 44 , 2640–2656.

    • Search Google Scholar
    • Export Citation

  • Rutledge, S. A., R. A. Houze, A. J. Heymsfield, and M. I. Biggerstaff, 1988: Dual-Doppler and airborne microphysical observations in the stratiform region of the 10-11 June MCS over Kansas during PRE-STORM. Preprints, 10th Int. Cloud Physics Conf., Bad Homburg, Germany, Deutscher Wetterdienst, 702–704.

    • Search Google Scholar
    • Export Citation

  • Smull, B. F., and R. A. Houze, 1985: A midlatitude squall line with a trailing region of stratiform rain: Radar and satellite observations. Mon. Wea. Rev., 113 , 117–133.

    • Search Google Scholar
    • Export Citation

  • Smull, B. F., and R. A. Houze, 1987a: Dual-Doppler radar analysis of a midlatitude squall line with a trailing region of stratiform rain. J. Atmos. Sci., 44 , 2128–2149.

    • Search Google Scholar
    • Export Citation

  • Smull, B. F., and R. A. Houze, 1987b: Rear inflow in squall lines with trailing stratiform precipitation. Mon. Wea. Rev., 115 , 2869–2889.

    • Search Google Scholar
    • Export Citation

  • Szeto, K. K., and H-R. Cho, 1994: A numerical investigation of squall lines. Part II: The mechanics of evolution. J. Atmos. Sci., 51 , 425–433.

    • Search Google Scholar
    • Export Citation

  • Tao, W-K., and J. Simpson, 1989: Modeling study of a squall-type convective line. J. Atmos. Sci., 46 , 177–202.

  • Wakimoto, R. M., H. V. Murphey, A. Nester, D. P. Jorgensen, and N. T. Atkins, 2006a: High winds generated by bow echoes. Part I: Overview of the Omaha bow echo 5 July 2003 storm during BAMEX. Mon. Wea. Rev., 134 , 2793–2812.

    • Search Google Scholar
    • Export Citation

  • Wakimoto, R. M., H. V. Murphey, C. A. Davis, and N. T. Atkins, 2006b: High winds generated by bow echoes. Part II: The relationship between the mesovortices and damaging straight-line winds. Mon. Wea. Rev., 134 , 2813–2829.

    • Search Google Scholar
    • Export Citation

  • Willis, P. T., and A. J. Heymsfield, 1989: Structure of the melting layer in mesoscale convective system stratiform precipitation. J. Atmos. Sci., 46 , 2008–2025.

    • Search Google Scholar
    • Export Citation

  • Yang, M-H., and R. A. Houze, 1995: Sensitivity of squall-line rear inflow to ice microphysics and environmental humidity. Mon. Wea. Rev., 123 , 3175–3193.

    • Search Google Scholar
    • Export Citation

  • Zipser, E. J., R. J. Meitín, and M. A. LeMone, 1981: Mesoscale motion fields associated with a slowly moving GATE convective band. J. Atmos. Sci., 38 , 1725–1750.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 218 62 3
PDF Downloads 139 37 0