• Asselin, R., 1972: Frequency filter for time integrations. Mon. Wea. Rev, 100 , 487490.

  • Brewster, K., 1984: Kinetic energy evolution in a developing severe thunderstorm. M.S. thesis, School of Meteorology, University of Oklahoma, Norman, OK, 171 pp.

    • Search Google Scholar
    • Export Citation
  • Brooks, H. E., C. A. Doswell III, and L. J. Wicker, 1993: STORMTIPE: A forecasting experiment using a three-dimensional cloud model. Wea. Forecasting, 8 , 352362.

    • Search Google Scholar
    • Export Citation
  • Davies-Jones, R., 1984: Streamwise vorticity: The origin of updraft rotation in supercell storms. J. Atmos. Sci, 41 , 29913006.

  • Dowell, D. C., and H. B. Bluestein, 1997: The Arcadia, Oklahoma, storm of 17 May 1981: Analysis of a supercell during tornadogenesis. Mon. Wea. Rev, 125 , 25622582.

    • Search Google Scholar
    • Export Citation
  • Droegemeier, K. K., S. M. Lazarus, and R. Davies-Jones, 1993: The influence of helicity on numerically simulated convective storms. Mon. Wea. Rev, 121 , 20052029.

    • Search Google Scholar
    • Export Citation
  • Durran, D. R., and J. B. Klemp, 1983: A compressible model for the simulation of moist mountain waves. Mon. Wea. Rev, 111 , 23412361.

  • Ellis, S., 1997: Holefilling data voids in meteorological fields. M.S. thesis, School of Meteorology, University of Oklahoma, Norman, OK, 198 pp.

    • Search Google Scholar
    • Export Citation
  • Gal-Chen, T., 1978: A method for initializing the anelastic equations: Implications for matching models with observations. Mon. Wea. Rev, 106 , 587606.

    • Search Google Scholar
    • Export Citation
  • Houze, R. A., 1993: Cloud Dynamics. Academic Press, 573 pp.

  • Janish, P. R., K. K. Droegemeier, M. Xue, K. Brewster, and J. Levit, 1995: Evaluation of the Advanced Regional Prediction System (ARPS) for storm-scale operational forecasting. Preprints, 14th Conf. on Weather Analysis and Forecasting, Dallas, TX, Amer. Meteor. Soc., 224–229.

    • Search Google Scholar
    • Export Citation
  • Johnson, D. E., P. K. Wang, and J. M. Straka, 1993: Numerical simulations of the 2 August 1991 CCOPE supercell storm with and without ice microphysics. J. Appl. Meteor, 32 , 745759.

    • Search Google Scholar
    • Export Citation
  • Kessler, E., 1969: On the Distribution of Continuity of Water Substance in Atmospheric Circulations. Meteor. Monogr., No. 32, Amer. Meteor. Soc., 84 pp.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., and D. K. Lilly, 1978: Numerical simulations of hydrostatic mountain waves. J. Atmos. Sci, 35 , 78107.

  • 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
  • Klemp, J. B., R. B. Wilhelmson, and P. S. Ray, 1981: Observed and numerically simulated structure of a mature supercell thunderstorm. J. Atmos. Sci, 38 , 15581580.

    • Search Google Scholar
    • Export Citation
  • Lilly, D. K., 1962: On the numerical simulation of buoyant convection. Tellus, 14 , 168172.

  • Lilly, D. K., 1986: The structure, energetics, and propagation of rotating convective storms. Part II: Helicity and storm stabilization. J. Atmos. Sci, 43 , 126140.

    • Search Google Scholar
    • Export Citation
  • Lilly, D. K., 1990: Numerical prediction of thunderstorms—has its time come? Quart. J. Roy. Meteor. Soc, 116 , 779798.

  • Lin, Y., P. S. Ray, and K. W. Johnson, 1993: Initialization of a modeled convective storm using Doppler radar–derived fields. Mon. Wea. Rev, 121 , 27572775.

    • Search Google Scholar
    • Export Citation
  • Liou, Y. C., 1989: Retrieval of three-dimensional wind and temperature fields from one component wind data by using the four-dimensional data assimilation technique. M.S. thesis, School of Meteorology, University of Oklahoma, Norman, OK, 112 pp.

    • Search Google Scholar
    • Export Citation
  • Lorenz, E. N., 1969: The predictability of flow which possesses many scales of motion. Tellus, 21 , 289307.

  • McCumber, M., W. K. Tao, J. Simpson, R. Penc, and S. T. Soong, 1991: Comparison of ice-phase microphysical parameterization schemes using numerical simulations of tropical convection. J. Appl. Meteor, 30 , 9851004.

    • Search Google Scholar
    • Export Citation
  • O'Brien, J. J., 1970: Alternative solutions to the classical vertical velocity problem. J. Appl. Meteor, 9 , 197203.

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

    • Search Google Scholar
    • Export Citation
  • Schlesinger, R. E., 1975: A three-dimensional numerical model of an isolated deep convective cloud: Preliminary results. J. Atmos. Sci, 32 , 934957.

    • Search Google Scholar
    • Export Citation
  • Shapiro, A., K. Droegemeier, S. Lazarus, and S. Weygandt, 1995a: Forward variational four-dimensional data assimilation and prediction experiments using a storm-scale numerical model. Proc. Int. Symp. on Assimilation of Observations in Meteorology and Oceanography, Tokyo, Japan, World Meteorological Organization, 361–366.

    • Search Google Scholar
    • Export Citation
  • Shapiro, A., S. Ellis, and J. Shaw, 1995b: Single-Doppler velocity retrievals with Phoenix II data: Clear air and microburst wind retrievals in the planetary boundary layer. J. Atmos. Sci, 52 , 12651287.

    • Search Google Scholar
    • Export Citation
  • Shapiro, A., L. Zhao, S. Weygandt, K. Brewster, S. Lazarus, and K. Droegemeier, 1996: Initial forecast fields created from single-Doppler wind retrieval, thermodynamic retrieval and ADAS. Preprints, 11th Conf. on Numerical Weather Prediction, Norfolk, VA, Amer. Meteor. Soc., 119–121.

    • Search Google Scholar
    • Export Citation
  • Smagorinsky, J., 1963: General circulation experiments with primitive equations. I. The basic experiment. Mon. Wea. Rev, 91 , 99164.

  • Sun, J., and A. Crook, 1996: Comparison of thermodynamic retrieval by the adjoint method with the traditional retrieval method. Mon. Wea. Rev, 124 , 308324.

    • Search Google Scholar
    • Export Citation
  • Sun, J., and A. Crook, 1999: Real-time boundary layer wind and temperature analysis using WSR-88D observations. Preprints, 29th Int. Conf. on Radar Meteorology, Montreal, Quebec, Canada, Amer. Meteor. Soc., 44–47.

    • Search Google Scholar
    • Export Citation
  • Taylor, W. L., Ed.,. 1982: 1981 spring program summary. NOAA Tech. Memo. ERL NSSL-93, 97 pp.

  • Vivekanandan, J., D. Zrnic, S. Ellis, R. Oye, A. Ryzhkov, and J. Straka, 1999: Cloud microphysics retrieval using S-band dual-polarization radar measurements. Bull. Amer. Meteor. Soc, 80 , 381388.

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

    • Search Google Scholar
    • Export Citation
  • Weygandt, S. S., K. K. Droegemeier, C. E. Hane, and C. L. Ziegler, 1990: Data assimilation experiments using a two-dimensional cloud model. Preprints, 16th Conf. on Severe Local Storms, Kananaskis Park, Alta., Canada, Amer. Meteor. Soc., 493–498.

    • Search Google Scholar
    • Export Citation
  • Weygandt, S. S., J. Levit, G. Basset, A. Shapiro, K. Brewster, R. Carpenter, M. Xue, and K. Droegemeier, 1999a: Real-time model initialization using single-Doppler retrieved fields obtained from WSR-88D level-II data. Preprints, 29th Int. Conf. on Radar Meteorology, Montreal, Quebec, Canada, Amer. Meteor. Soc., 150–153.

    • Search Google Scholar
    • Export Citation
  • Weygandt, S. S., P. Nutter, E. Kalnay, S. Park, and K. Droegemeier, 1999b: The relative importance of different data fields in a numerically simulated convective storm. Preprints, Eighth Conf. on Mesoscale Processes, Boulder, CO, Amer. Meteor. Soc., 310–315.

    • Search Google Scholar
    • Export Citation
  • Weygandt, S. S., A. Shapiro, and K. K. Droegemeir, 2002: Retrieval of model initial fields from single-Doppler observations of a supercell thunderstorm. Part I: Single-Doppler velocity retrieval. Mon. Wea. Rev, 130 , 433453.

    • Search Google Scholar
    • Export Citation
  • Wicker, L. J., M. P. Kay, and M. P. Foster, 1997: STORMTIPE-95: Results from a convective storm forecast. Wea. Forecasting, 12 , 388398.

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

    • Search Google Scholar
    • Export Citation
  • Xue, M., K. K. Droegemeier, V. Wong, A. Shapiro, and K. Brewster, 1995: ARPS User's Guide, Version 4.0. Center for Analysis and Prediction of Storms, 380 pp.

    • Search Google Scholar
    • Export Citation
  • Xue, M., K. K. Droegemeier, and V. Wong, 2000: The Advanced Regional Prediction System (ARPS)—A multiscale nonhydrostatic atmospheric simulation and prediction tool. Part I: Model dynamics and verification. Meteor. Atmos. Phys, 75 , 161193.

    • Search Google Scholar
    • Export Citation
  • Xue, M., and and Coauthors, 2001: The Advanced Regional Prediction System (ARPS)—A multiscale nonhydrostatic atmospheric simulation and prediction tool. Part II: Model physics and applications. Meteor. Atmos. Phys, 75 , 161193.

    • Search Google Scholar
    • Export Citation
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Retrieval of Model Initial Fields from Single-Doppler Observations of a Supercell Thunderstorm. Part II: Thermodynamic Retrieval and Numerical Prediction

Stephen S. WeygandtCenter for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, Oklahoma

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Alan ShapiroCenter for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, Oklahoma

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Kelvin K. DroegemeierCenter for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, Oklahoma

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Abstract

In this two-part study, a single-Doppler parameter retrieval technique is developed and applied to a real-data case to provide model initial conditions for a short-range prediction of a supercell thunderstorm. The technique consists of the sequential application of a single-Doppler velocity retrieval (SDVR), followed by a variational velocity adjustment, a thermodynamic retrieval, and a moisture specification step. In Part I, the SDVR procedure is described and results from its application to a supercell thunderstorm are presented. In Part II, results from the thermodynamic retrieval and the numerical model prediction for this same case are presented. For comparison, results from parallel sets of experiments using dual-Doppler-derived winds and winds obtained from the simplified velocity retrieval described in Part I are also shown.

Following the SDVR, the retrieved wind fields (available only within the storm volume) are blended with a base-state background field obtained from a proximity sounding. The blended fields are then variationally adjusted to preserve anelastic mass conservation and the observed radial velocity. A Gal-Chen type thermodynamic retrieval procedure is then applied to the adjusted wind fields. For all experiments (full retrieval, simplified retrieval, and dual Doppler), the resultant perturbation pressure and potential temperature fields agree qualitatively with expectations for a deep-convective storm. An analysis of the magnitude of the various terms in the vertical momentum equation for both the full retrieval and dual-Doppler experiments indicates a reasonable agreement with predictions from linear theory. In addition, the perturbation pressure and vorticity fields for both the full retrieval and dual-Doppler experiments are in reasonable agreement with linear theory predictions for deep convection in sheared flow.

Following a simple moisture specification step, short-range numerical predictions are initiated for both retrieval experiments and the dual-Doppler experiment. In the full single-Doppler retrieval and dual-Doppler cases, the general storm evolution and deviant storm motion are reasonably well predicted for a period of about 35 minutes. In contrast, the storm initialized using the simplified wind retrieval decays too rapidly, indicating that the additional information obtained by the full wind retrieval (primarily low-level polar vorticity) is vital to the success of the numerical prediction. Sensitivity experiments using the initial fields from the full retrieval indicate that the predicted storm evolution is strongly dependent on the initial moisture fields. Overall, the numerical prediction results suggest at least some degree of short-term predictability for this storm and provide an impetus for continued development of single-Doppler retrieval procedures.

* Current affiliation: NOAA Office of Atmospheric Research, Forecast Systems Laboratory, Boulder, Colorado.

Corresponding author address: Stephen S. Weygandt, NOAA Forecast Systems Laboratory, 325 Broadway, R/FS1, Boulder, CO 80305-3328. Email: weygandt@fsl.noaa.gov

Abstract

In this two-part study, a single-Doppler parameter retrieval technique is developed and applied to a real-data case to provide model initial conditions for a short-range prediction of a supercell thunderstorm. The technique consists of the sequential application of a single-Doppler velocity retrieval (SDVR), followed by a variational velocity adjustment, a thermodynamic retrieval, and a moisture specification step. In Part I, the SDVR procedure is described and results from its application to a supercell thunderstorm are presented. In Part II, results from the thermodynamic retrieval and the numerical model prediction for this same case are presented. For comparison, results from parallel sets of experiments using dual-Doppler-derived winds and winds obtained from the simplified velocity retrieval described in Part I are also shown.

Following the SDVR, the retrieved wind fields (available only within the storm volume) are blended with a base-state background field obtained from a proximity sounding. The blended fields are then variationally adjusted to preserve anelastic mass conservation and the observed radial velocity. A Gal-Chen type thermodynamic retrieval procedure is then applied to the adjusted wind fields. For all experiments (full retrieval, simplified retrieval, and dual Doppler), the resultant perturbation pressure and potential temperature fields agree qualitatively with expectations for a deep-convective storm. An analysis of the magnitude of the various terms in the vertical momentum equation for both the full retrieval and dual-Doppler experiments indicates a reasonable agreement with predictions from linear theory. In addition, the perturbation pressure and vorticity fields for both the full retrieval and dual-Doppler experiments are in reasonable agreement with linear theory predictions for deep convection in sheared flow.

Following a simple moisture specification step, short-range numerical predictions are initiated for both retrieval experiments and the dual-Doppler experiment. In the full single-Doppler retrieval and dual-Doppler cases, the general storm evolution and deviant storm motion are reasonably well predicted for a period of about 35 minutes. In contrast, the storm initialized using the simplified wind retrieval decays too rapidly, indicating that the additional information obtained by the full wind retrieval (primarily low-level polar vorticity) is vital to the success of the numerical prediction. Sensitivity experiments using the initial fields from the full retrieval indicate that the predicted storm evolution is strongly dependent on the initial moisture fields. Overall, the numerical prediction results suggest at least some degree of short-term predictability for this storm and provide an impetus for continued development of single-Doppler retrieval procedures.

* Current affiliation: NOAA Office of Atmospheric Research, Forecast Systems Laboratory, Boulder, Colorado.

Corresponding author address: Stephen S. Weygandt, NOAA Forecast Systems Laboratory, 325 Broadway, R/FS1, Boulder, CO 80305-3328. Email: weygandt@fsl.noaa.gov

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