Analysis of the inner-core characteristics of Noel (2007) during its extratropical transition

On November 2 2007, Hurricane Noel began to undergo extratropical transition (ET) as it interacted with a mid-latitude trough east of the southeast United States. This study presents a detailed analysis of Noel during the early stages of its ET, documenting the chronology of the physical processes during the transition. Low-level (600-950 hPa) dropwindsonde and in-situ observations from the NOAA WP-3D aircraft and the Aerosonde unmanned aircraft indicated that Noel maintained a warm core (tilting to the east with height) while being initially classified as an extratropical cyclone. A preliminary analysis of the upper level structure of Noel, as determined by AMSU, also indicated a warm core. Flight-level profiles of potential temperature indicated that the approaching cold front was 700km to the southwest of the center. Noel exhibited some unusual characteristics, including a strong asymmetry with a wind maximum at 150km to the SE of the center according to the SFMR. Furthermore, tangential winds were observed to decrease with height on the east side, and increase with height on the west side. A detailed cyclone phase space analysis and thermodynamic analysis using the multiple aircraft and satellite-based data will be presented to elucidate the physical mechanisms that were altering Noel's characteristics during the period of observation.