It was demonstrated, using estimates of nearby soundings, that the maximum horizontal wind speeds in tornadoes exceed the thermodynamic speed limit ( Snow and Pauley 1984 Fiedler and Rotunno 1986). (1993) showed how a portable, low-power, CW (continuous wave) Doppler radar could be used during severe storm intercept field programs to increase the number of tornado datasets, provide visual documentation, and obtain measurements below cloud base. Unfortunately, the NSSL was unable to obtain simultaneous visual documentation of the tornadoes, and since most of the tornadoes probed were relatively far from the radar site, the center of the radar volume was at or above cloud base.īluestein and Unruh (1989) and Bluestein et al. A summary of Doppler wind spectra in tornadoes computed from a fixed-site pulsed Doppler radar at the National Severe Storms Laboratory (NSSL) is found in Bluestein and Golden (1993). The shape of the Doppler wind spectrum can be used to infer some properties of the tornado wind field when the radar volume is approximately the same size as or slightly greater than that of the tornado vortex. Wind spectra are more meaningful than mean Doppler velocities when there is a large variation in wind speed in the volume probed by the radar ( Brown et al. Zrnić and Doviak (1975) showed how Doppler wind velocity spectra can be used to estimate the maximum horizontal wind speeds in tornadoes. Remote sensing by radar has proven to be a safer, easier, and more productive technique than attempts to make in situ measurements. A review of efforts to make wind measurements and map the wind field in tornadoes is given in Bluestein and Golden (1993). Real wind data are needed to verify theories for the structure and evolution of tornadoes. The tornado’s parent vortex (mesocyclone) was approximately 2 km in diameter and contained tangential wind speeds of 45–50 m s −1. Circumstantial evidence is presented that the tornado originated along an elliptically shaped cyclone/shear zone along the leading edge of a large hook echo in its parent supercell storm. Wind speeds of 60 m s −1 were indicated in the tornado in a swath 300 m across, with some smaller areas of possible wind speeds up to 75 m s −1. This study is unique in that both ground-based and airborne Doppler radar systems probed the tornado and its environment.
Lubbock texas radar in motion portable#
The CW spectra computed from data collected by the portable radar, a pseudo-dual-Doppler analysis of airborne Doppler radar data collected by a National Oceanic and Atmospheric Administration P-3 aircraft, photogrammetric analysis of a video of the tornado, and a ground-based damage survey are discussed in the context of the FM-CW spectra. The FM-CW radar data from the tornado are the first ever collected of high enough quality to analyze. Doppler wind velocity spectra of the tornado and its parent circulation, which were computed from data collected by a low-power, portable, FM-CW (frequency-modulated continuous-wave), 3-cm-wavelength Doppler radar, are presented at increments in the range of 78 m. An analysis of the tornado and its parent storm is discussed.
Lubbock texas radar in motion verification#
A large tornado was observed near Northfield, Texas, on during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX).
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