Observations of a Severe Left Moving Thunderstorm

Lewis D. Grasso Cooperative Institute for Research in the Atmosphere, Fort Collins, Colorado

Search for other papers by Lewis D. Grasso in
Current site
Google Scholar
PubMed
Close
and
Eric R. Hilgendorf Cooperative Institute for Research in the Atmosphere, Fort Collins, Colorado

Search for other papers by Eric R. Hilgendorf in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Observations have shown that right moving thunderstorms are favored in environments characterized by clockwise-turning hodographs. There are, however, a few observational and numerical studies of long-lived, left moving storms within environments characterized by clockwise-turning hodographs. For example, a documented left mover that occurred on 26 May 1992, near Coldspring, Texas, with a mesoanticyclone and hail spike (also called a three-body scattering signature) produced severe weather. Although a few cases have been documented, left moving thunderstorms have received less study than right moving cells.

The long-lived, severe thunderstorm of 17 May 1996 is presented to improve documentation of left moving thunderstorms. The storm occurred over eastern Nebraska and will be referred to as the York County storm. This left mover resulted from storm splitting and moved to the west of a surface cold front. The relatively isolated storm subsequently split approximately 1 h later, yielding a new right moving thunderstorm. Doppler radial velocities suggested the existence of a mesoanticyclone within the York County storm. Hail, 1.75 in. in diameter, was produced by the storm around the time the updraft split.

There were many similarities between the York County storm and the 26 May 1992 Coldspring left moving severe thunderstorm. Both storms were relatively isolated, contained mesoanticyclones, and produced severe weather after the vertically integrated liquid water obtained a maximum value. Due to the dearth of material on left-moving storms, general statements concerning their evolution are lacking. This current study is a first step toward improving the sparse documentation of such thunderstorms. More work is needed in this area to help identify physical processes that lead to left moving thunderstorms, particularly those that become severe.

Corresponding author address: Dr. Lewis D. Grasso, NOAA/NESDIS/RAMMT CIRA, Colorado State University, West Laporte Avenue, Fort Collins, CO 80523. Email: grasso@genesis.cira.colostate.edu

Abstract

Observations have shown that right moving thunderstorms are favored in environments characterized by clockwise-turning hodographs. There are, however, a few observational and numerical studies of long-lived, left moving storms within environments characterized by clockwise-turning hodographs. For example, a documented left mover that occurred on 26 May 1992, near Coldspring, Texas, with a mesoanticyclone and hail spike (also called a three-body scattering signature) produced severe weather. Although a few cases have been documented, left moving thunderstorms have received less study than right moving cells.

The long-lived, severe thunderstorm of 17 May 1996 is presented to improve documentation of left moving thunderstorms. The storm occurred over eastern Nebraska and will be referred to as the York County storm. This left mover resulted from storm splitting and moved to the west of a surface cold front. The relatively isolated storm subsequently split approximately 1 h later, yielding a new right moving thunderstorm. Doppler radial velocities suggested the existence of a mesoanticyclone within the York County storm. Hail, 1.75 in. in diameter, was produced by the storm around the time the updraft split.

There were many similarities between the York County storm and the 26 May 1992 Coldspring left moving severe thunderstorm. Both storms were relatively isolated, contained mesoanticyclones, and produced severe weather after the vertically integrated liquid water obtained a maximum value. Due to the dearth of material on left-moving storms, general statements concerning their evolution are lacking. This current study is a first step toward improving the sparse documentation of such thunderstorms. More work is needed in this area to help identify physical processes that lead to left moving thunderstorms, particularly those that become severe.

Corresponding author address: Dr. Lewis D. Grasso, NOAA/NESDIS/RAMMT CIRA, Colorado State University, West Laporte Avenue, Fort Collins, CO 80523. Email: grasso@genesis.cira.colostate.edu

Save
  • Achtemeier, G. L., 1969: Some observations of splitting thunderstorms over Iowa on August 25–26, 1965. Preprints, Sixth Conf. on Severe Local Storms, Chicago, IL, Amer. Meteor. Soc., 89–94.

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

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bluestein, H. B., and Sohl C. J. , 1979: Some observations of a splitting thunderstorm. Mon. Wea. Rev, 107 , 861873.

  • Boe, B. A., and Coauthors. . 1992: The North Dakota Thunderstorm Project: A cooperative study of high plains thunderstorms. Bull. Amer. Meteor. Soc, 73 , 145160.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Brown, R. A., and Meitin R. J. , 1994: Evolution and morphology of two splitting thunderstorms with dominant left moving members. Mon. Wea. Rev, 122 , 20522067.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Charba, J., and Sasaki V. , 1971: Structure and movement from severe thunderstorms of 3 April 1964 as revealed by radar and surface mesonetwork data analysis. J. Meteor. Soc. Japan, 49 , 191213.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davies-Jones, R. P., 1985: Tornado dynamics. Thunderstorm Morphology and Dynamics. 2d ed., E. Kessler, Ed., University of Oklahoma Press, 197–236.

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

    • Search Google Scholar
    • Export Citation
  • Dutton, J. A., 1986: The Ceaseless Wind. An Introduction to the Theory of Atmospheric Motion. Dover Press, 579 pp.

  • Fujita, T., and Grandoso H. , 1968: Split of a thunderstorm into anticyclonic and cyclonic storms and their motion as determined from numerical model experiments. J. Atmos. Sci, 25 , 416439.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grasso, L. D., 2000: The dissipation of a left moving cell in a severe storm environment. Mon. Wea. Rev, 128 , 27972815.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grasso, L. D., and Cotton W. R. , 1995: Numerical simulation of a tornado vortex. J. Atmos. Sci, 52 , 11921203.

  • Klemp, J. B., and Wilhemlson R. B. , 1978: Simulations of right and left moving storms produced through storm splitting. J. Atmos. Sci, 35 , 10971110.

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

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lemon, L. R., 1995: Recognition of the radar three-body scatter spike as a large hail signature. Preprints, 27th Conf. on Radar Meteorology, Vail, CO, Amer. Meteor. Soc., 533–535.

    • Search Google Scholar
    • Export Citation
  • National Climatic Data Center, 1996: Storm Data. Vol. 38, No. 5, 458 pp.

  • Nielsen-Gammon, J. W., and Read W. L. , 1995: Detection and interpretation of left moving severe thunderstorms using the WSR-88D: A case study. Wea. Forecasting, 10 , 127140.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • OFCM, 1990: Doppler radar meteorological observations, Part C, WSR-88D products and algorithms. Federal Meteorological Handbook, FCM-H11C-1991, Interim Version One, Office of the Federal Coordinator for Meteorology, Rockville, MD, 210 pp.

    • Search Google Scholar
    • Export Citation
  • Rotunno, R., and Klemp J. B. , 1982: The influence of the shear-induced pressure gradient on thunderstorm motion. Mon. Wea. Rev, 110 , 136151.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., 1985: On the rotation and propagation of simulated supercell thunderstorms. J. Atmos. Sci, 42 , 271292.

  • Schlesinger, R. E., 1980: A three dimensional numerical model of an isolated thunderstorm. Part II: Dynamics of updraft splitting and mesovortex couplet evolution. J. Atmos. Sci, 37 , 395420.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., and Klemp J. B. , 1984: The structure and classification of numerically simulated convective storms in directionally varying wind shear. Mon. Wea. Rev, 112 , 24792498.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weisman, M. L., and Rotunno R. , 2000: The use of vertical wind shear versus helicity in interpreting supercell dynamics. J. Atmos. Sci, 57 , 14521472.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilhelmson, R. B., and Klemp J. B. , 1981: A three dimensional numerical simulation of splitting severe storms on 3 April 1964. J. Atmos. Sci, 38 , 15811600.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilson, J. W., and Reum D. , 1986: The hail spike: Reflectivity and velocity signature. Preprints, 23d Conf. on Radar Meteorology, Snowmass, CO, Amer. Meteor. Soc., R62–R65.

    • Search Google Scholar
    • Export Citation
  • Winston, H. A., and Ruthi L. J. , 1986: Evaluation of RADAP II severe-storm detection algorithms. Bull. Amer. Meteor. Soc, 67 , 145150.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 283 45 3
PDF Downloads 111 32 0