The 15 May 2003 Shamrock, Texas, supercell: A dual-Doppler analysis and EnKF data-assimilation experiment (Formerly Paper 15.8)

During the evening of 15 May 2003, a dual-Doppler dataset was collected, at a low elevation angle, through a supercell in the Texas Panhandle (near Shamrock) using the U. Mass., mobile, X-band radar and the SMART-R, mobile, C-band radar. During the time data were collected, damage consistent with a tornado occurred approximately 15 km (20 km) away from the U. Mass. (SMART) radar. Data collection from both radars encloses the time period when damage consistent with a tornado was occurring. The data collected by both radars were used to construct a high spatial resolution dual-Doppler analysis of the storm. In addition, volumetric data were collected by the C-band Doppler radar. After editing several volumes of data, an ensemble Kalman filter (EnKF) was employed in an attempt to retrieve temperature and wind fields. The wind retrievals will allow for a comparison between the EnKF low-level winds and the winds from the dual-Doppler analysis. Other results of the dual-Doppler analysis and EnKF experiment also will be presented in an attempt to gauge the accuracy of the data assimilation experiment results and understand various unique aspects of the storm, including the cyclic nature of mesocyclogenesis in the supercell that occurred prior to the strongest damage near Shamrock.