Abstract:By means of the CINRAD/CD and WSR88D hail indexes, the hail data from January 2005 to August 2007 is analyzed. The hail indexes, such as warning threshold, relative radar height, missing report rate, false alarm rate, POD/FAR/CSI (Probability of Detection/False Acceptance Rate/Critical Success Index), are calculated and compared with SHI (Severe Hail Index), which is used as a prediction factor of the hail size, and the actual and predicted hail sizes are compared. Considering the local environment and climate characteristics, attempts to improve FAR are made (inputting the correct heights of 0 ℃ (-20 ℃), and increasing the reflectivity), and a method for reducing FAR is discussed. Using the method, the hail events from January 2007 to August 2007 are analyzed and tested, and the results show that FARs are reduced, and the forecast sizes of hailstones are closer to the actual sizes.