Observations of Tornadoes and Other Convective Phenomena with a Mobile, 3–mm Wavelength, Doppler Radar: The Spring 1999 Field Experiment

Abstract

In the spring of 1999 a field experiment was conducted in the Southern Plains of the United States, during which a mobile, millimeter?wavelength pulsed Doppler radar from the University of Massachusetts, Amherst, was used by a storm?intercept team from the University of Oklahoma to collect data in tornadoes and developing tornadoes. With a 0.18° beam antenna, resolution as high as 5?10 m in the azimuthal direction was attained in a tornado on 3 May. Data collected in three supercell tornadoes are described. Features such as eyes, spiral bands, and multiple vortices/wavelike asymmetries along the edge of the eyewall are discussed. Winds approaching 80 m s?1 were resolved without folding using the polarization diversity pulse pair technique. Two tornadoes formed at an inflection point in reflectivity where the hook echo and apparent rear?flank downdraft intersected. Finescale transverse bands of reflectivity were evident in one hook echo. Data in a dust devil are also described. Numerous other datasets collected in mesocyclones are also noted. A plan for future data analysis is suggested and a plan for future experiments and upgrades to the radar are proposed.