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In July 2005, the National Aeronautics and Space Administration investigated tropical cyclogenesis, hurricane structure, and intensity change in the eastern North Pacific and western Atlantic using its ER-2 high-altitude research aircraft. The campaign, called the Tropical Cloud Systems and Processes (TCSP) experiment, was conducted in conjunction with the National Oceanic and Atmospheric Administration/ Hurricane Research Division's Intensity Forecasting Experiment. A number of in situ and remote sensor datasets were collected inside and above four tropical cyclones representing a broad spectrum of tropical cyclone intensity and development in diverse environments. While the TCSP datasets directly address several key hypotheses governing tropical cyclone formation, including the role of vertical wind shear, dynamics of convective bursts, and upscale growth of the initial vortex, two of the storms sampled were also unusually strong, early season storms. Highlights from the genesis missions are described in this article, along with some of the unexpected results from the campaign. Interesting observations include an extremely intense, highly electrified convective tower in the eyewall of Hurricane Emily and a broad region of mesoscale subsidence detected in the lower stratosphere over landfalling Tropical Storm Gert.

Representing the effects of cumulus parameterization in numerical models, known as cumulus parameterization, is of fundamental importance in atmospheric sciences. Despite a significant amount of effort devoted to improving the understanding of the parameterization problem, a general theory of cumulus parameterization does not exist. The problem is particularly difficult for a mesoscale model with a grid size of 1-20 km, because at such a resolution, a numerical model introduces an artificial spectral gap by splitting an organized mesoscale convective system into resolvable and subgrid scales of motions. To provide a forum for a focused discussion on the problem of cumulus parameterization for mesoscale models, the Mesoscale and Microscale Meteorology Division of NCAR conducted a mini workshop on 11-12 September 1995 in Boulder, Colorado. Approximately 50 scientists participated in this workshop. The workshop was organized into six sessions: 1) overview of the cumulus parameterization problem, 2) cloud model perspectives, 3) model sensitivity to convective parameterization, 4) mesoscale organization and momentum transport, 5) mesoscale observations and verification of schemes, and 6) summary and general discussion. The scientific presentations and the discussion are summarized from reports submitted by the session chairs.