Numerical Techniques for the Analysis of Digital Radar Data with Applications to Meteorology and Hydrology.

Investigation has been conducted on the feasibility of utilizing digital radar data for "real-time" meteorological and hydrologic applications. Numerical techniques have been developed that enhance the usefulness of weather radar data in these applications. Falling within the scope of this study was an investigation of various coordinate systems, interpolation procedures, and grid intervals. It is demonstrated that a quadratic interpolation procedure and a 2 nm x 2 nm rectangular coordinate system preserve the characteristics of storms required for severe weather forecasting and hydrologic applications. Through the use of digital radar data measured at successive elevation angles in a storm system, an analysis technique is developed that presents a new dimension in mesoscale analysis and gives' means of detecting areas of "explosive development" in severe storms. This indicator presents the three-dimensional characteristics of a storm system in a two-dimension display of vertically-integrated liquid-water content (VIL). Constant altitude reflectivity maps (CAZM), CAPPI type displays, which are useful in mesoanalysis and/or the study of thunderstorm dynamics, also may be generated from digital radar data. Although a CAZM illustrates the echo or storm intensity at various constant levels, to identify precisely the most intense echoes it is necessary to look at the CAZM for each level and integrate mentally the intensities through the depth of the storm. This procedure fails to reveal clearly the "explosive development" in storms, a shortcoming that is not suffered by VIL. ...