Abstract:Based on the statistical analysis of the CIND3830 CC CINRAD data and surface observation data, the statistical characteristics of ‘V’ notch and the relationship between the ‘V’ notch and surface hail event at Pu’er observation during 2004-2013 are analyzed. The application of ‘V’ notch for hail early warning and the influence of ‘V’ notch for short term forecast are discussed as well. The results show that: (1) The best observation elevation ranges of the ‘V’ notch are from 0.5 to 2.4 degree elevation while the height that the ‘V’ notch occurs ranges from 2.1 to 6.5 km. (2) The ‘V’ notch can be divided into two types, the first one is at the radial back of massive echo cell while the second one is located in the radial back of schistose or massive echo multi cells. (3) The composition reflectivity of typeⅠ ‘V’ notch ranges from 50 to 66 dBz, generally equal or greater than 55 dBz, with a hail occurrence probability of 69%. (4) The composite reflectivity of type Ⅱ ‘V’ notch ranges from 47 to 64 dBz, generally around 50 to 55 dBz, with a hail occurrence probability of 29%. (5) Hail event can be forecasted when the ‘V’ notch is observed and H45 dBz≥7.5 km, CR≥55 dBz with the rate of accuracy up to 100%. The early warning for ‘V’ notch is 5-102 min early. In addition, the identification method for hail echo in ‘V’ notch is studied.