Design Of Storm Cell Identification And Tracking Program Based On SCIT And Analysis Of Hail Cloud’s Radar Echo Characteristics In Jianghuai Area Of Anhui Province

The detection and forecasting of hail storms based on the Doppler Weather Radar is one of the important functions of the Doppler Weather Radar facility of meso-scale ad micro-scale disaster weather system. Analysis to hail cloud’s radar echo characteristic in Jianghuai area in Anhui Province, have an important significance to hail suppression of artificial influence weather in this area. According to storm cell identification and tracking algorithm and Hail detecting algorithm of WSR-88D,we designed program to identify and track hail storm, output storm tracking products and Hail Index. The algorithm is transplanted to CAPPI and polarization weather radar based on in-depth study of WSR-88D SCIT algorithm and we achieved good results.We analyzed hail cloud’s radar echo characteristic in Anhui Province by the program designed statistically.We utilized surface hail data in Anhui province from 2002 to 2013, radar data observed by New Generation Weather Radar (CINRAD) in Hefei and balloon sounding data. Hail data was used for selecting examples, Doppler Weather radar data was used for statistical analysis, balloon sounding data mainly used in the calculating the height of 0℃ and -20 ℃. Echo intensity, cold layer thickness, hail index and VIL of storm cell are statistically analyzed. Some algorithm threshold of hail index and VIL of storm cell are summarized,which has an reference value for weather recognition and forecasting of hail cloud.The results show that:the time of highest probability of hail is in June and July in a year in Anhui Province. In a day, it is from afternoon to evening (15～18). The hail cloud’s reflectivity is 55dBZ at least, most 60-70dBZ in Anhui in spring and summer. VIL of hail storm is 30kg·m-2 at least, most 40～80 kg·m-2. Change trends of VIL of hail storm and maximum reflectivity are similar. Maximum of VIL of hail appears in the vicinity of hail time. Average of echo top of hail storm is 13.6km in Anhui in spring and summer. Average of Top storm height of 30dBZ is 12.1km. The maximum echo top height is above 17km. Through statistics on hail cloud’s radar echo characteristic in Jianghuai area in Anhui Province, we should pay close attention to the possibility of hail occurrence when the cloud’s reflectivity is above 55dBZ and the height of 45dBZ is in 4.3km above and cold layer thickness of more than 6km.