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Howard B. Bluestein, Eugene W. McCaul Jr., Gregory P. Byrd, and Gary R. Woodall

)ABSTRACT- On 7 May 1986 thunderstorms formed during the afternoon near a dryline in the Texas Panhandle underweak synoptic-scale forcing. Five tornadoes and large hail were produced by one storm near Canadian, Texas.The focus of the paper is the analysis of soundings obtained by a storm-intercept crew. A sounding launchedinto the wall cloud of the storm just after the fourth tornado indicated a nearly pseudomoist adiabatic lapserate, a temperature excess of 10-C over the environment at 500 mb, and an

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Chun-Chih Wang, Daniel J. Kirshbaum, and David M. L. Sills

-breeze-forced moist convection. Moreover, the prominent low- to midlevel drying in the July case likely further reduced parcel buoyancy through entrainment (e.g., Rousseau-Rizzi et al. 2017 ). 4. Numerical simulations To provide a more quantitative analysis of the larger-scale and mesoscale forcing of deep convection in the two study cases, we conduct cloud-resolving, real-case numerical simulations using the Weather Research and Forecasting (WRF) Model, version 3.8.1 ( Skamarock et al. 2008 ). WRF is a

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Wayne M. Angevine, Hongli Jiang, and Thorsten Mauritsen

soundings and surface forcing identical to those in the LES, providing a clean comparison with the boundary layer scheme isolated from any other influences. We find good agreement in the simulated vertical transport and resulting moisture profiles at the end of each 11-h run. Notable differences are seen in the cloud base, higher in TEMF due to more top entrainment and no inertia; in the cloud top; and in the distribution of moisture between the lower and upper cloud layer. We argue that the top

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N. E. Davidson and G. J. Holland

-rain.producing monsoon depressions over northern Australia. Two aspects are considered: (a)the large-scale forcing, using both synoptic flow field changes and angular momentum budgets, and (b) the roleof convective and stratiform clouds, using kinematic and thermodynamic budgets. For each situation, the Northern Hemisphere circulation becomes favorable well prior to genesis. The shortterm trigger for development is the strengthening of the Southern Hemisphere subtropical ridge at the surfaceand an amplifying

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Chung-Chieh Wang, George Tai-Jen Chen, Hsiao-Ling Huang, Richard E. Carbone, and Sau-Wa Chang

distribution of identified cases and their composites, we employ the Tropical Rainfall Measuring Mission (TRMM) 3B42 merged satellite rain rates, with a horizontal resolution of 0.25° × 0.25° at 3-h intervals ( Huffman et al. 2007 ). Since the TRMM data are available only since 1998, cases in 1997 (accounting for 11% of the sample) were not included in the composites. Table 2. Cases of propagating cloud episodes used for composites in the four types with strong 500-hPa synoptic forcing (i.e., types listed

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Richard S. Hemler, Frank B. Lipps, and Bruce B. Ross

with observations and with a higher-resolution model simulationin an environment of similar shear, suggesting that the 5-km horizontal resolution is adequately representingthe significant features of the squall line.The major shortcoming of this study is the failure of the cloud model to produce the observed squall line atthe proper time. Without the observed small-scale forcing, which was unresolved in the Severe EnvironmentalStorms and Mesoscale Experiment (SESAME) dataset, the model is unable to

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D. Gregory and P. R. Rowntree

empirical formulaMz= lO-3c[(ovP)k-I -- (ovE)k-I -- b]/Aak-l/2 (S-1) (25)wherec is 3.33 x 10-4i.e., the initial mass flux is proportional to the excessbuoyancy of the parcel starting from layer k in layerk-1. This approach is different from the assumption thata quasi-equilibrium exists between convection, largescale and boundary layer forcing used in some convection schemes. In the Arakawa-Schubert scheme itis assumed that convection and large-scale forcing actto maintain a constant cloud work

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Robert G. Fovell and Peter S. Dailey

-directed dynamic component has intensified. At 28 500 s ( Figs. 11c,g ), the dynamic acceleration component is particularly strong for the highlighted parcel and is directed toward the rotationally induced dynamic low at the rear flank of the growing cloud and updraft (see Figs. 5c and 9c ). By the final time, 29 100 s ( Figs. 11d,h ), latent heating has wanted substantially, and the background circulation has again become dominant. 4) Forcing of the brief, intense downdraft In Fig. 5 , it was seen that a

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Olli Turpeinen

suppression can be attributed to the circulation ofthe adjacent cell forcing the inner downdrafts to develop inside the lateral boundaries of the clouds. In'contrast, the ulashear cell behaves like an isolated one, due to the increased moisture flux from the directionof the downshear cell. The sensitivity tests on the varying timing and intensity of the two impulses showthat neither the use of non-simultaneous nor non-identical impulses promote merging. On the contrary, theminimum edge-to-edge separation

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Qingfang Jiang, Shouping Wang, and Larry O’Neill

very thin, especially in the presence of clouds (Wang et al. 2010, manuscript submitted to Atmos. Chem. Phys. ). The jet extends approximately 1000 km offshore over the ocean, and is significantly stronger during the strong-forcing period than the weak-forcing period ( Figs. 6a,b ). Over the coastal area, the alongshore wind component is northerly above the inversion, associated with the reversal of the zonal potential temperature gradient. This relatively narrow elevated northerly jet can be

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