Comparison of Radar Rainfall Nowcasting Performance between S-PROG and LINDA Techniques

Abstract

The weather radar technology has been widely accepted for nowcasting rainfall and has the potential to enhance the efficiency of early warning systems. However, it is still necessary to verify the suitable of nowcasting techniques for specific regions based on their rainfall patterns and topography. This study aimed to investigate the effectiveness of two nowcasting techniques, namely the S-PROG and LINDA, in order to determine an efficient approach for nowcasting rainfall patterns within the Sattahip radar radius. Reflectivity data from the Sattahip Radar Station at 6-minute intervals was collected and the lead-time for nowcasting was set at 6, 12, ..., 120 minutes during 14 heavy rain events in 2021. The results of the study indicated that the S-PROG technique was capable of nowcasting rainfall on a large scale but lacked the ability to simulate small-scale rainfall clouds. Conversely, the LINDA technique was able to simulate a variety of rainfall patterns, including merging, splitting, and preservation of the center of the storm. The effectiveness of the nowcasting techniques was evaluated using the Critical Success Index (CSI) and Correlation metrics. The results showed that the LINDA demonstrated superior qualitative and quantitative performance which outperformed the S-PROG technique. The range of CSI values for the S-PROG and LINDA techniques were 0.87 - 0.45 and 0.81 - 0.42, respectively. The range of correlation values for the S-PROG and LINDA techniques were 0.85 - 0.15 and 0.89 - 0.18, respectively.