The Propagation of Convective Outflow through Oklahoma City During Joint Urban 2003

During June and July 2003, Joint Urban 2003 (JU2003), the largest urban dispersion field experiment ever, was conducted in Oklahoma City. JU2003 focused on understanding atmospheric processes within and around the urban environment. An extremely dense observing network was installed in and around downtown Oklahoma City including over 140 3-D sonic anemometers for surface-based and tower-based measurements, 13 2-D sonic anemometers, over 30 surface meteorological stations, seven surface energy budget stations, two CTI wind tracer lidars, three radiosonde systems, three wind profiler/RASS systems, one FM-CW radar, three ceilometers, and nine sodars (including midi- and mini-sodars). The JU2003 instrumentation was supported by observations from the Oklahoma Mesonet, four WSR-88D Doppler radars, and the OUN upper air station.

During the early morning hours of 30 July 2003, convective storms moved through the Oklahoma City metro area. In advance of the precipitation, an outflow boundary propagated through the dense network of sensors installed downtown during JU2003. Initial analysis revealed that exposed locations experienced a dramatic wind shift and gusts that exceeded 14 m/s. However, the impact of the outflow at the urban canyon sites was much reduced (limited wind shift and wind speeds approximately 5 m/s). This study will quantify the horizontal and vertical motions at numerous locations within the urban environment as the outflow boundary approached and passed through Oklahoma City.