Based on daily observation data and disaster data from automatic weather stations in Hedong region of Gansu Province from 2008 to 2017, the 75 hail cases were selected with some standards and divided into three types according to main weather influencing system of hail and mesoscale diagnostic method, including the northwestern airstream, the low trough and the low vortex types. Then statistical characteristics of radar products and radar echo feature under the three weather types of hail were compared, and the typical hail cases were chosen to verify the results. The results show that the maximum reflectivity (Z_max) and the height of maximum reflectivity ( H_{Z_{\mathrm{m}\mathrm{a}\mathrm{x}}}) had relatively little differences under the three weather types of hail, Z_max was above 50 dBZ and H_{Z_{\mathrm{m}\mathrm{a}\mathrm{x}}} was above 2.0 km. There were significant differences in echo top height (ET), core area thickness (H), center height of echo reflectivity above 45 dBZ (H_{45 dBZ}), the maximum height of storm body echo reflectivity equal to or more than 30 dBZ (TOP), vertically integrated liquid water content (VIL), and the density of vertically integrated liquid water content (VILD). The H, H_{45 dBZ}, TOP and VIL of the northwestern airstream type were significantly higher than those of other types, and ET of the low trough type and VILD of the low vortex type were lower. The frequencies of overhang echo for the three types of hail weather were all higher than 61.0%. The frequencies of three body scattering and side-lobe echo for the the low trough type were 35.5% and 48.4%, respectively, and the probability of bounded weak echo was 12.9%. The frequencies of bounded weak echo area for both of the northwestern airstream type and the low vortex type were higher than 38.5%. The indicators of three body scattering and side-lobe echo could predict the hail weather 18 to 30 minutes in advance, which had some significance in hail weather forecast.

Recently，frequent occurrence of extreme weather and climate events had caused serious impacts on people s production and livelihood，so the extended － range weather forecast attracted more and more attention． With the national spread and promotion of the low － frequency synoptic chart，extended － range synoptic processes forecast was developing vigorously throughout the country． To better satisfy the service need of synoptic processes forecast，an on － line displaying system associated with the extended － range synoptic processes forecast was developed in Zhejiang Climate Center． In this paper，the design philosophy，detailed structure，and the thoughts of future improvement and optimization were introduced extensively． The on － line displaying system included two columns，i． e． ，the heavy rainfall processes and the intensive air － temperature reduction processes based on different objects of forecast． The column of heavy rainfall processes consisted of the figure comparing between forecast and the actual state，forecast document，table of dynamic scores，table of brief description of the realistic observation，and table of detailed description of the realistic observation． The contents of intensive air － temperature reduction processes column were similar to that of the heavy rainfall processes，but the table of dynamic scores was omitted． In the future，the system will receive more improvement and optimization through designing more suitable indices and establishing the marking scheme for intensive air － temperature reduction processes and expanding the components of extended-range synoptic processes forecast．