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Richard Rotunno

core radii and peak velocities in modeled atmospheric vortices. J. Atmos. Sci., 36, 2413-2424.Brandes, E. A., 1978: Mesocyclone evolution and tornadogenesis: Some observations. Mort. Wea. Rev., 106, 995-10t 1.Church, C. R., and J. T. Snow, 1979: The dynamics of natural tornadoes as inferred from laboratory simulations. J. Rech. At mos., 13, 111-133. , --, G. L. Baker and E. M. Agee, 1979: Characteristics of tornado-like vortices as a function of swirl ratio: a laboratory investigation

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Robert Davies-Jones

derivation closely parallelsprevious work on tornadogenesis (Davies-Jones 1982).Then, an equation is obtained that relates the materialderivative of thermal-wind imbalance to a generalizedQ vector Q* and ageostrophic terms, and a PE versionof the omega equation also is found. The generalizedQ vector is the vector mean of the OM and the Sutcliffeet al. forms of the Q vector, with geostrophic velocitygradients replaced by actual ones. In section 4, the quasi-geostrophic Q vector (Q inthe nomenclature

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W. S. Lewellen
,
D. C. Lewellen
, and
R. I. Sykes

simulation. Thus our results do not address the question of tornadogenesis but deal with the question of how the details of the low-level, tornado flow depend upon larger-scale features in the thunderstorm represented by the boundary conditions on our domain. Different thunderstorms undoubtedly exhibit a wide variety of detailed velocity distributions on an inner domain boundary corresponding to the edges of our computational domain. In this paper, we restrict our attention to one possible set of

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Alan Shapiro
,
Katherine M. Willingham
, and
Corey K. Potvin

: TITAN: Thunderstorm Identification, Tracking Analysis and Nowcasting—A radar-based methodology. J. Atmos. Oceanic Technol. , 10 , 785 – 797 . 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 , 2562 – 2582 . Dowell , D. C. , and H. B. Bluestein , 2002 : The 8 June 1995 McLean, Texas, Storm. Part I: Observations of cyclic tornadogenesis. Mon. Wea. Rev. , 130 , 2626

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Susan C. van den Heever
and
William R. Cotton

.1 until the vertical grid spacing reached 2000 m, above which it was kept constant. The model top extended beyond 23 km above ground level (AGL), and there were nine model levels within the first kilometer AGL. These grid spacings are sufficient to resolve storm-scale features and processes, but are insufficient to simulate tornadogenesis. The long time step was 5 s. The basic radiative condition was applied at the lateral boundaries ( Klemp and Wilhelmson 1978a ), a Rayleigh friction layer was

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Cynthia K. Mueller
and
Richard E. Carbone

updraftalong the trailing gust front and the vault updraft. Between the two updraft cores is a downdraft. The downdraft is first apparent at 2230. It increases in size andmagnitude throughout the lifetime of the vortex. Noprecipitation is associated with the downdraft. Therefore it must be a dynamically driven downdraft, withprecipitation loading and diabatic cooling effects absent. This is a very significant finding which is particularly applicable to issues in tornadogenesis.8. Discussion This study

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Julien Baerenzung
,
D. Rosenberg
,
P. D. Mininni
, and
A. Pouquet

, whereas in a tornado the rotation has a somewhat uncertain origin ( Rotunno 1984 ; Rotunno and Klemp 1985 ): it is thought to be linked to the preexistence of a downdraft that, together with precipitation introduced as in Markowski et al. (2003) , transports angular momentum to the ground where the circulation is then closed [see Wicker and Wilhelmson (1995) , and references therein]. More recent studies of tornadogenesis have included the effects of moisture and buoyancy, together with

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Enoch Jo
and
Sonia Lasher-Trapp

.1175/1520-0469(1981)038<1558:OANSSO>2.0.CO;2 . Lasher-Trapp , S. , E. Jo , L. R. Allen , B. N. Engelsen , and R. J. Trapp , 2021 : Entrainment in a simulated supercell thunderstorm. Part I: The evolution of different entrainment mechanisms and their dilutive effects . J. Atmos. Sci. , 78 , 2725 – 2740 , https://doi.org/10.1175/JAS-D-20-0223.1 . Lemon , L. R. , and C. A. Doswell III , 1979 : Severe thunderstorm evolution and mesocyclone structure as related to tornadogenesis . Mon. Wea. Rev

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J. Rosinski
,
K. A. Browning
,
G. Langer
, and
C. T. Nagamoto

implications for hail suppression. Tech. Rept. 75/1,* 75 pp, National Hail Research Experiment, NCAR. '.. , J. C. Fankhauser, J.-P. Chalon, P. J. Eccles, R. G. Strauch, 'F. H. Merrem, D. J. Musil, E. L. May and W. R. Sand, 1975: Structure of an evolving hailstorm. Part -: Synthesis. Sub mitted to Mon. Wea. Rev.Bujwid, O., 1888: Die Bakterien 'in Hagelk/Srnern. Zbl. Bakt., 3, 1-2.Danielsen, E. F., 1976: A conceptual theory of tornadogenesis. Submitted to Mon. Wea. Rev.Dennis, A. S

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Joseph B. Klemp
and
Richard Rotunno

inadequate physicsin the model equations or to insufficient numericalresolution. Certainly the absence of surface drag andthe simplification of microphysical and' turbulenceprocesses through parameterization might contributeto these discrepancies. However, we hypothesize thatnumerical resolution is the primary limitation in simulating the occlusion processes occurring during tornadogenesis, subject to verification in these experiments. In seeking to enhance numerical resolution withinthe storm

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