A 40-year climatology of extratropical transition in the eastern North Pacific

Extratropical transition, the process by which a tropical cyclone's energy source shifts from latent heat release in a warm core to baroclinic processes with a cold core as it moves poleward into the mid-latitude flow, has been frequently observed in many tropical basins around the world, including the western North Pacific, the northern Atlantic, and the southwestern Pacific. Conversely, only rare cases have been documented in the eastern North Pacific. This presentation will showcase a climatology of extratropical transition in this basin from 1970 to 2010. This study utilizes 6-hourly reanalysis data from the European Centre for Medium-Range Weather Forecasts at a nominal resolution of 0.703 degrees from 1979 onward (ERA-Interim) and a nominal resolution of 1.125 degrees before 1979 (ERA-40) to produce cyclone phase space plots as well as examine the large-scale features present during extratropical transition in the eastern North Pacific.