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Walter A. Petersen, Robert C. Cifelli, Steven A. Rutledge, Brad S. Ferrier, and Bradley F. Smull

Shipborne Doppler radar operations were conducted over the western Pacific warm pool during TOGA COARE using the Massachusetts Institute of Technology and NOAA TOGA C-band Doppler radars. Occasionally the ships carrying these radars were brought to within 50 km of each other to conduct coordinated dual-Doppler scanning. The dual-Doppler operations were considered a test of the logistical and engineering constraints associated with establishing a seagoing dual-Doppler configuration. A very successful dual-Doppler data collection period took place on 9 February 1993 when an oceanic squall line developed, intensified, and propagated through the shipborne dual-Doppler lobes. Later on the same day, NOAA P-3 aircraft sampled a more intense squall line located approximately 400 km to the southeast of the shipborne operations. This study provides an overview of the shipborne dual-Doppler operations, followed by a comparison of the kinematic and precipitation structures of the convective systems sampled by the ships and aircraft. Special emphasis is placed on interpretation of the results relative to the electrical characteristics of each system.

Soundings taken in the vicinity of the ship and aircraft cases exhibited similar thermodynamic instability and shear. Yet Doppler radar analyses suggest that the aircraft case exhibited a larger degree of low-level forcing, stronger updrafts, more precipitation mass in the mixed-phase region of the clouds, and a relatively higher degree of electrification as evidenced by lightning observations. Conversely, convection in the ship case, while producing maximum cloud-top heights of 16 km, was associated with relatively weaker low-level forcing, weaker vertical development above the −5°C level, moderate electric fields at the surface, and little detectable lightning. Differences in the kinematic and precipitation structures were further manifested in composite vertical profiles of mean convective precipitation and vertical motion. When considered relative to the electrical properties of the two systems, the results provide further circumstantial evidence to support previously hypothesized vertical velocity and radar reflectivity thresholds that must be exceeded in the 0° to −20°C regions of tropical cumulonimbi prior to the occurrence of lightning.

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Raul A. Valenzuela and David E. Kingsmill

(left) in the Northern (Southern) Hemisphere with a radius of curvature determined by their wind speed and the Coriolis parameter (e.g., Steenburgh et al. 1998 ). This effect can be enhanced when an offshore-directed gap flow joins a large-scale onshore-directed airflow, a phenomenon observed by Loescher et al. (2006) along the coast of Alaska. A detailed understanding of TTA kinematic structure is essential for clarifying how TTAs impact the intensity and spatial distribution of orographic

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Stephanie A. Weiss, Donald R. MacGorman, and Kristin M. Calhoun

that some microphysical process or kinematic interaction occurred in the anvil to enhance the electric field locally. Without something of the sort, one would have expected the electric field to decrease with distance as the anvil material was advected downstream. Kuhlman et al. (2009) also pointed out that, in some respects, the issue of maintaining and increasing electric field magnitudes in an anvil is similar to the issue of maintaining and increasing the electric field observed in the

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Jake P. Mulholland, Jeffrey Frame, Stephen W. Nesbitt, Scott M. Steiger, Karen A. Kosiba, and Joshua Wurman

; Kristovich et al. (2017) ; data available online at http://data.eol.ucar.edu/master_list/?project=OWLeS ], occurred during the winter of 2013/14. Stemming from the successes of the exploratory LLAP project, the OWLeS project sought to examine 1) the kinematics and dynamics of LLAP bands, 2) upwind and downwind lake influences (i.e., heat and moisture fluxes and advection) on lake-effect convection, and 3) orographic influences on lake-effect convection. The original OWLeS proposal planned for eight

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Anthony C. Didlake Jr., Gerald M. Heymsfield, Lin Tian, and Stephen R. Guimond

-to-moderate precipitation. The w field ( Fig. 11c ) shows consistent features with stratiform precipitation, including small magnitudes (<2 m s −1 ) throughout most of the domain. Updrafts are dominant above the bright band. Below this level, downdrafts are prominent, but a clear exception of positive w values occurs toward the beginning of the domain and at 4-km altitude. These exceptions, which are inconsistent with typical stratiform kinematics, are likely a result of errors in the fall speed correction and

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Han Wang and Oliver Bühler

kinematic Helmholtz decomposition is indicative of the robustness of geostrophic balance, a further dynamical wave–vortex decomposition that can tell different dynamic components apart is certainly more desirable ( BCF14 ). Due to lack of potential energy measurements (such as buoyancy) in the LASER drifter observations, we are currently unable to conduct this further step exactly. If structure functions of buoyancy, or other indicators of potential energy are available, a generalization of the BCF14

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J. W. Deardorff

MARCH 1981 NOTES AND CORRESPONDENCE 659NOTES AND CORRESPONDENCEFurther Considerations on the Reynolds Average of the Kinematic Boundary Condition J. W. DEARDORFFDepartment of Atmospheric Sciences, Oregon State University, Corvallis 9733113 October 1980i. l[ntroduction In the paper by Deardorff and Pcterson (1980,hereafter denoted DP), the kinematic boundary condition between two distinct

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B. Vonnegut

1042 MONTHLY WEATHER REVIEW VOLU~ 124Comments on "Three-Dimensional Kinematic and Microphysical Evolution of Florida Cumulonimbus" B. VONNEOrrrState University of New York at Albany, Albany, New York26 September 1995 and 20 October 1995 In their introduction Yuter and Houze (1995a) discuss the history of downdrafts in cumulonimbus cloudsand refer to The

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Christopher J. Schultz, Lawrence D. Carey, Elise V. Schultz, and Richard J. Blakeslee

size and/or magnitude for a lightning jump to occur based on previously reported evidence linking upward trends in kinematic and microphysical properties to increases in total flash rate (e.g., Carey and Rutledge 1996 ; Lang and Rutledge 2002 ; Tessendorf et al. 2005 ; Kuhlman et al. 2006 ; Deierling and Petersen 2008 ). Certainly, numerous studies illustrate good correlation between updraft volume, precipitation mass ice production, and flash rate (e.g., Workman and Reynolds 1949 ; Dye et

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R. A. Kropfli and L. S. Miller

520JOURNAL OF THE ATMOSPHERIC SCIENCESVOLUME 33Kinematic Structure and Flux Quantities in a Convective Storm from Dual-Doppler Radar Observations R. A. Kxox, r~ ~ L. J. Mn.i.~.a Wave Propagation Laboratory, NOAA, Boulder, Colo. 80302(Manuscript received 14 April 1975, in revised form 13 November 1975) The NOAA/WPL dual-Doppler radar system has been used to determine the three-dimensional kinematicstructure of a convective storm during its

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