Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review in 2003. Methods for diagnosing ET in reanalysis, observational, and model-forecast datasets are discussed. New climatologies for the eastern North Pacific and southwest Indian Oceans are presented alongside updates to western North Pacific and North Atlantic Ocean climatologies. Advances in understanding and, in some cases, modeling the direct impacts of ET-related wind, waves, and precipitation are noted. Improved understanding of structural evolution throughout the transformation stage of ET fostered in large part by novel aircraft observations collected in several recent ET events is highlighted. Predictive skill for operational and numerical model ET-related forecasts is discussed along with environmental factors influencing posttransition cyclone structure and evolution. Operational ET forecast and analysis practices and challenges are detailed. In particular, some challenges of effective hazard communication for the evolving threats posed by a tropical cyclone during and after transition are introduced. This review concludes with recommendations for future work to further improve understanding, forecasts, and hazard communication.

[1] Subtropical cyclogenesis and tropical transitions (TT) over the South Atlantic Ocean only received attention after the first documented Hurricane Catarina occurred close to the southern Brazilian coast in March 2004. However, due to the lack of studies in this part of the Atlantic Ocean, it is still unclear what the main environmental conditions and dynamical processes associated with TT or even subtropical cyclogenesis are over the region. This study presents a synoptic and dynamical analysis of the subtropical cyclone Anita which occurred in March 2010 near the Brazilian coast. This system started as a pure subtropical cyclone, evolved to a condition favorable to TT, later developed into a cold-core structure, and decayed as an extratropical cyclone. During the period favorable for TT, the turbulent heat fluxes (latent plus sensible) from the ocean decreased, and Anita started interacting with another extratropical disturbance, preventing the TT to happen. This interaction, in turn, increased the vertical wind shear, allowed the extratropical transition to occur, and promoted the westward displacement of Anita to colder waters, thus decreasing the turbulent heat fluxes. The results suggest that the combination of a dipole blocking pattern aloft, with contribution from barotropic energy conversions, and strong turbulent fluxes is an important ingredient for tropical storm development. Hybrid storms in such environmental conditions can be one form of precursors of hurricanes over the South Atlantic.Citation: Dias Pinto, J. R., M. S. Reboita, and R. P. da Rocha (2013), Synoptic and dynamical analysis of subtropical cyclone Anita (2010) and its potential for tropical transition over the South Atlantic Ocean,

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