This thesis addresses the extratropical transition (ET) of tropical cyclones. Such a definition would have utility for the operational community by providing a standardized time to designate extratropical transition. During an ET event, wind fields often expand dramatically, resulting in more widely-felt impacts. It gets intensified any part of extratropical regions of the Earth (usually between 30° and 60° latitude from the equator), either through cyclogenesis or extratropical transition. Extratropical: A term used in advisories and tropical summaries to indicate that a cyclone has lost its "tropical" characteristics. Only one of the three transition types needed has been previously well-studied. Almost half of all tropical cyclones (TCs) in the Atlantic basin undergo extratropical transition (ET). There would also be several benefits for the research community, including a consistent designation in the best-track records for ET with associated criteria that are physically based but easily understood. New Metric for Defining the Time of Extratropical Transition of Tropical Cyclones. ET is the process by which a tropical cyclone, upon encountering a baroclinic environment at higher latitudes, loses its tropical characteristics and transforms into an extratropical cyclone. This extratropical transition layer (ExTL) is discussed in section 4. Moreover, the heaviest precipitation typically shifts to the left-of-center (LOC), which can result in inland flash flooding hundreds of kilometers from the cyclone center. Basically, it is a gradual transformation of a TC into a system with extratropical characteristics while moving pole - ward into a more baroclinic environment with higher wind shear, a larger Coriolis parameter, and lower sea Results, Comments and Future Work Tropical cyclones often transform into extratropical cyclones at the end of their tropical existence, usually between 30° and 40° latitude, where there is sufficient forcing from upper-level troughs or shortwaves riding the Westerlies for the process of extratropical transition to begin.  The thermal tropopause as defined by the WMO definition is often multivalued, exhibits breaks near jet streams, and does not form a continuous three‐dimensional surface globally. Keywords: tropical cyclones, extratropical transition, operational analyses, clustering 1. Extratropical Transition (ET)–Development pathway involving the transition of a tropical cyclone into an extratropical cyclone NASA Group Activity Identify the following: Comma cloud Dry Slot Warm, cold, and occluded front Expected precipitation areas Possible precipitation bands NASA Group Activity through transition. There is no general definition of extratropical transition (ET) of TCs (Malmquist 1999). A brief description of the alternate types of transitions is given, along with illustrative storms, to assist with further study. AJAY RAGHAVENDRA* and SHAWN M. MILRAD † Meteorology Program, Embry-Riddle Aeronautical University Daytona Beach, Florida *Corresponding Author e-mail: firstname.lastname@example.org † Research Advisor . … Using fine-scale observations of chemical tracers, we look for answers to a set of questions: What is a more meaningful definition of the extratropical tropopause when investigating STE of chemical tracers? tropopauses identify the chemical transition from tropo-sphere to stratosphere.