Comparisons of Simulated Kinematic and Moisture Fields with Airborne In-situ and Doppler Radar Observations in a Convective Cold Front over the Eastern Pacific Ocean

During the PACJET field program, the NOAA P-3 aircraft sampled a strong, convective cold front over the eastern Pacific Ocean off the coast of Southern California. The flight track was such to permit both along-front and cross-front cross-sections of in-situ thermodynamic and kinematic data as well as obtaining Doppler radar data from the intense precipitation. Reflectivities along the narrow cold-frontal rainband (NCFR) reached over 50 dBz, and the NCFR was organized into typical core and gap regions. MM5 simulations of this case used grid-spacings to 1.7 km while maintaining an adequate grid-spacing aspect ratio. The simulations are validated with the thermodynamic and kinematic fields diagnosed from the in-situ aircraft and dropsonde data and the Doppler radar data. Of particular interest are the kinematic, thermodynamic, and turbulent structure of the low-level jet (LLJ) region in the warm sector just ahead of the cold front, its along-front variability, and the mesoscale kinematic and thermodynamic structure associated with the NCFR and the wide cold-frontal rainband trailing the cold front. This comparison between the modeled storm structure and the P-3 data is complementary to the comparison between the modeled storm structure and the TRMM data to be presented by Braun et al., and it is suggested that the two presentations be back-to-back.