• Barnes, S. L., 1973: Mesoscale objective analysis using weighted time-series observations. NOAA Tech. Memo. ERL NSSL-62, National Severe Storms Laboratory, Norman, OK, 60 pp. [NTIS COM-73-10781].

    • Search Google Scholar
    • Export Citation
  • Brock, F. V., , K. C. Crawford, , R. L. Elliott, , G. W. Cuperus, , S. J. Stadler, , H. L. Johnson, , and M. D. Eilts, 1995: The Oklahoma Mesonet: A technical overview. J. Atmos. Oceanic Technol., 12 , 519.

    • Search Google Scholar
    • Export Citation
  • Bryan, G. H., , and M. L. Weisman, 2006: Mechanisms for the production of severe surface winds in a simulation of an elevated convective system. Preprints, 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., 7.5.

    • Search Google Scholar
    • Export Citation
  • Bryan, G. H., , D. A. Ahijevych, , C. Davis, , S. B. Trier, , and M. Weisman, 2005: Observations of cold pool properties in mesoscale convective systems during BAMEX. Preprints, 11th Conf. on Mesoscale Processes, Albuquerque, NM, Amer. Meteor. Soc., JP5J.12.

    • Search Google Scholar
    • Export Citation
  • Charba, J., 1974: Application of gravity current model to analysis of squall-line gust front. Mon. Wea. Rev., 102 , 140156.

  • Cressman, G. P., 1959: An operational objective analysis system. Mon. Wea. Rev., 87 , 367374.

  • Duchon, C. E., 1979: Lanczos filtering in one and two dimensions. J. Appl. Meteor., 18 , 10161022.

  • Engerer, N. A., , D. J. Stendsrud, , and M. C. Coniglio, 2008: Surface characteristics of observed cold pools. Mon. Wea. Rev., 136 , 48394849.

    • Search Google Scholar
    • Export Citation
  • Evans, J. S., , and C. A. Doswell, 2001: Examination of derecho environments using proximity soundings. Wea. Forecasting, 16 , 329342.

  • Fovell, R. G., 2002: Upstream influence of numerically simulated squall-line storms. Quart. J. Roy. Meteor. Soc., 128 , 893912.

  • Fujita, T. T., 1955: Results of detailed synoptic studies of squall lines. Tellus, 7 , 405436.

  • Fujita, T. T., 1978: Manual of downburst identification for project NIMROD. SMRP Research Paper 156, University of Chicago, 104 pp. [NTIX PB-28604801].

    • Search Google Scholar
    • Export Citation
  • Gallus Jr., W. A., , and R. H. Johnson, 1991: Heat and moisture budgets of an intense midlatitude squall line. J. Atmos. Sci., 48 , 122146.

    • Search Google Scholar
    • Export Citation
  • Glickman, T. S., Ed. 2000: Glossary of Meteorology. 2nd ed. Amer. Meteor. Soc., 855 pp.

  • Haertel, P. T., , and R. H. Johnson, 2000: The linear dynamics of squall line mesohighs and wake lows. J. Atmos. Sci., 57 , 93107.

  • Haertel, P. T., , R. H. Johnson, , and S. N. Tulich, 2001: Some simple simulations of thunderstorm outflows. J. Atmos. Sci., 58 , 504516.

  • Hilgendorf, E., , and R. Johnson, 1998: A study of the evolution of mesoscale convective systems using WSR-88D data. Wea. Forecasting, 13 , 437452.

    • Search Google Scholar
    • Export Citation
  • Houze, R. A., , M. I. Biggerstaff, , S. A. Rutledge, , and B. F. Smull, 1989: Interpretation of Doppler weather radar displays of midltatiude mesoscale convective systems. Bull. Amer. Meteor. Soc., 70 , 608619.

    • 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 , 613654.

    • Search Google Scholar
    • Export Citation
  • Hoxit, L. R., , C. F. Chappel, , and J. M. Fritsch, 1976: Formation of mesolows or pressure troughs in advance of cumulonimbus clouds. Mon. Wea. Rev., 104 , 14191428.

    • Search Google Scholar
    • Export Citation
  • Jorgensen, D. P., , H. V. Murphey, , and R. M. Wakimoto, 2004: Rear-inflow evolution in a non-severe bow echo observed by airborne Doppler radar during BAMEX. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., 4.6.

    • Search Google Scholar
    • Export Citation
  • Johns, R. H., , and W. D. Hirt, 1987: Derechos: Widespread convectively induced windstorms. Wea. Forecasting, 2 , 3249.

  • Johnson, B. C., 1983: The heat burst of 29 May 1976. Mon. Wea. Rev., 111 , 17761792.

  • Johnson, R. H., , and P. J. Hamilton, 1988: The relationship of surface pressure features to the precipitation and air flow structure of an intense midlatitude squall line. Mon. Wea. Rev., 116 , 14441472.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., 1994: On the dynamics of gravity currents in a channel. J. Fluid Mech., 269 , 169198.

  • Klimowski, B. A., 1994: Initiation and development of rear inflow within the June 28–29 North Dakota mesoconvective system. Mon. Wea. Rev., 122 , 765779.

    • Search Google Scholar
    • Export Citation
  • Klimowski, B. A., , R. Przybylinski, , G. Schmocker, , and M. R. Hjelmfelt, 2000: Observations of the formation and early evolution of bow echoes. Preprints, 20th Conf. of Severe Local Storms, Orlando, FL, Amer. Meteor. Soc., 44–47.

    • Search Google Scholar
    • Export Citation
  • Klimowski, B. A., , M. J. Bunkers, , M. R. Hjelmfelt, , and J. N. Covert, 2003: Severe convective windstorms over the northern high plains of the United States. Wea. Forecasting, 18 , 502519.

    • Search Google Scholar
    • Export Citation
  • Knievel, J. C., , and R. H. Johnson, 1998: Pressure transients with MCS mesohighs and wake lows. Mon. Wea. Rev., 126 , 19071930.

  • Lafore, J-P., , and M. W. Moncrieff, 1989: A numerical investigation of the organization and interaction of the convective and stratiform regions of tropical squall lines. J. Atmos. Sci., 46 , 31443176.

    • Search Google Scholar
    • Export Citation
  • Loehrer, S. M., , and R. H. Johnson, 1995: Surface pressure and precipitation life cycle characteristics of PRE-STORM mesoscale convective systems. Mon. Wea. Rev., 123 , 600621.

    • Search Google Scholar
    • Export Citation
  • Mapes, B. E., 1993: Gregarious tropical convection. J. Atmos. Sci., 50 , 20262037.

  • 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.

    • Search Google Scholar
    • Export Citation
  • Nuss, W. A., , and D. W. Titley, 1994: Use of multiquadric interpolation for meteorological objective analysis. Mon. Wea. Rev., 122 , 16111631.

    • Search Google Scholar
    • Export Citation
  • Pandya, R. E., , and D. R. Durran, 1996: The influence of convectively generated thermal forcing on the mesoscale circulation around squall lines. J. Atmos. Sci., 53 , 29242951.

    • Search Google Scholar
    • Export Citation
  • Parker, M. D., 2008: Response of simulated squall lines to low-level cooling. J. Atmos. Sci., 65 , 13231341.

  • Parker, M. D., , and R. H. Johnson, 2000: Organizational modes of midlatitude convective systems. Mon. Wea. Rev., 128 , 34133436.

  • Parker, M. D., , and J. C. Knievel, 2005: Do meteorologists suppress thunderstorms?: Radar-derived statistics and the behavior of moist convection. Bull. Amer. Meteor. Soc., 86 , 341358.

    • Search Google Scholar
    • Export Citation
  • Przybylinski, R., 1995: The bow echo: Observations, numerical simulations, and severe weather detection methods. Wea. Forecasting, 10 , 203218.

    • Search Google Scholar
    • Export Citation
  • Rotunno, F., , J. B. Klemp, , and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci., 45 , 463485.

  • 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.

    • Search Google Scholar
    • Export Citation
  • Skamarock, W., , M. Weisman, , and J. Klemp, 1994: Three-dimensional evolution of simulated long-lived squall lines. J. Atmos. Sci., 51 , 25632584.

    • Search Google Scholar
    • Export Citation
  • Smull, B. F., , and R. A. Houze, 1987: Rear inflow in squall lines with trailing stratiform precipitation. Mon. Wea. Rev., 115 , 28692889.

    • Search Google Scholar
    • Export Citation
  • Stumpf, G., , R. Johnson, , and B. Smull, 1991: The wake low in a midlatitude mesoscale convective system having complex organization. Mon. Wea. Rev., 119 , 134158.

    • Search Google Scholar
    • Export Citation
  • Trapp, R. J., , and M. Weisman, 2003: Low-level mesovortices within squall lines and bow echoes. Part II: Their genesis and implications. Mon. Wea. Rev., 131 , 28042823.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., 1982: Life cycle of thunderstorm gust fronts as viewed with Doppler radar and rawinsonde data. Mon. Wea. Rev., 110 , 10601082.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R. M., , H. V. Murphey, , C. A. Davis, , 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 , 27932812.

    • Search Google Scholar
    • Export Citation
  • Wakimoto, R., , H. Murphey, , C. Davis, , and N. Atkins, 2006b: High winds generated by bow echoes. Part II: The relationship between the mesovortices and damaging straight-line winds. Mon. Wea. Rev., 134 , 28132829.

    • Search Google Scholar
    • Export Citation
  • Weisman, M., 1992: The role of convectively generated rear-inflow jets in the evolution of long-lived mesoconvective systems. J. Atmos. Sci., 49 , 18261847.

    • Search Google Scholar
    • Export Citation
  • Weisman, M., 1993: The genesis of severe, long-lived bow echoes. J. Atmos. Sci., 50 , 645670.

  • Weisman, M., , and R. J. Trapp, 2003: Low-level mesovortices within squall lines and bow echoes. Part I: Overview and dependence on environmental shear. Mon. Wea. Rev., 131 , 27792803.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 64 64 13
PDF Downloads 67 67 8

Mesoscale Surface Pressure and Temperature Features Associated with Bow Echoes

View More View Less
  • 1 Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado
© Get Permissions
Restricted access

Abstract

This study examines observed mesoscale surface pressure, temperature, and wind features of bow echoes. Bow-echo events in the area of the Oklahoma Mesonet are selected for study to take advantage of high-resolution surface data. Thirty-six cases are identified using 2-km-resolution radar reflectivity data over a 4-yr period (2002–05); their surface features are interrogated using the mesonet data. Distinct surface features usually associated with squall lines, the mesohigh and cold pool, are found to also accompany bow echoes. A common surface pattern preceding bowing is identified. Prior to new bowing development, the mesohigh surges ahead of the convective line while the cold pool remains centered behind it. Surface winds shift to a ground-relative outflow pattern upon arrival of the mesohigh surge. Approximately 30 min later, a new bowing segment forms with its apex slightly to the left (with respect to the direction of system motion) of the mesohigh surge. The cold pool follows the convective line as it bows. This process is termed the “pressure surge–new bowing” cycle, and a conceptual model is presented. In one representative case, the surface signature of a gravity wave, identified through spatial and temporal filtering, is tracked. It is presumed to be generated by deep heating within the convective line. The wave moved at nearly 35 m s−1 and has heretofore been undetected in mesoanalysis studies. Two other distinct features, a sharp pressure rise and temperature drop, were also observed at all mesonet stations affected by the system. Possible explanations for these features in terms of a gravity current, gravity wave, or atmospheric bore are explored.

Corresponding author address: Rebecca D. Adams-Selin, HQ Air Force Weather Agency 2 WXG/WEA, 101 Nelson Dr., Offutt AFB, NE 68113. Email: rebecca.selin.ctr@offutt.af.mil

Abstract

This study examines observed mesoscale surface pressure, temperature, and wind features of bow echoes. Bow-echo events in the area of the Oklahoma Mesonet are selected for study to take advantage of high-resolution surface data. Thirty-six cases are identified using 2-km-resolution radar reflectivity data over a 4-yr period (2002–05); their surface features are interrogated using the mesonet data. Distinct surface features usually associated with squall lines, the mesohigh and cold pool, are found to also accompany bow echoes. A common surface pattern preceding bowing is identified. Prior to new bowing development, the mesohigh surges ahead of the convective line while the cold pool remains centered behind it. Surface winds shift to a ground-relative outflow pattern upon arrival of the mesohigh surge. Approximately 30 min later, a new bowing segment forms with its apex slightly to the left (with respect to the direction of system motion) of the mesohigh surge. The cold pool follows the convective line as it bows. This process is termed the “pressure surge–new bowing” cycle, and a conceptual model is presented. In one representative case, the surface signature of a gravity wave, identified through spatial and temporal filtering, is tracked. It is presumed to be generated by deep heating within the convective line. The wave moved at nearly 35 m s−1 and has heretofore been undetected in mesoanalysis studies. Two other distinct features, a sharp pressure rise and temperature drop, were also observed at all mesonet stations affected by the system. Possible explanations for these features in terms of a gravity current, gravity wave, or atmospheric bore are explored.

Corresponding author address: Rebecca D. Adams-Selin, HQ Air Force Weather Agency 2 WXG/WEA, 101 Nelson Dr., Offutt AFB, NE 68113. Email: rebecca.selin.ctr@offutt.af.mil

Save