Single- and Multiple-Doppler Radar Observations of Tornadic Storms

Abstract

The use of one, two, three or more Doppler radars has become increasingly common in research programs. The advantage in increasing the number of radars is in the increased area covered and the accuracy with which wind estimates may be obtained. Although multiple-radar systems can yield special quantitative insight, a great deal of information can still be determined in real time from a single radar. It should be noted that the interpretation of radial velocity estimates from a single radar are not always unambiguous. Color displays of single-Doppler radial velocity patterns aid in the real-time interpretation of the associated reflectivity fields and can reveal important features not evident in the reflectivity structures alone. Such a capability is of particular interest in the identification and study of severe storms. A display utilizing a 5 cm Doppler radar is used to illustrate the patterns seen from several tornadic storms that occurred in central Oklahoma on 20 May 1977. Interpretation of some complicated or ambiguous features is aided by including data from additional radars. Further explanations on such structure are given from an analysis based on a new dual-Doppler analysis technique for one of 16 tornadic storms that occurred on 20 May 1977. Several alternative analysis schemes for two to four Doppler radars are also demonstrated and compared. These illustrate the major differences found in error propagation, use of information, and in difference quantities, such as divergence. It is shown that an analysis that specifies boundary values for w is not strongly dependent on the number of radars.