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.