The 15 May 2003 Shamrock, Texas, supercell: A dual-Doppler analysis and EnKF data-assimilation experiment

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. The former also collected dual-polarization data. During the time data were collected, a tornado formed approximately 15 km (20 km) away from the U. Mass. (SMART-R) radar. Data collection began 20 minutes prior to tornadogenesis and continued through the lifetime of the tornado. This dataset allows a unique look at the wind field during tornadogenesis. Volumetric data were also 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 pressure 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 along with any relevant dual-Polarization observations.