Abstract:A comparative analysis is made of a hail process at Ninghe County on 15 July 2002 and a heavy precipitation at Tianjin on 16 August 2005 by using of weather maps, cloud images, and Tianjin CINRAD/SA products. The emphasis is put on the echoes of mesoscale systems on the velocity field and the image features on the intensity field. The results indicate that though the influencing systems for the two processes are different, there appeared supercell storms on the radar echo images of both, with the heavy supercell accompanying a heavy rain of 77.5 mm per hour and the weak one having hailstones of about 40 mm in diameter. The characteristics on the velocity chart are different too. The heavy precipitation supercell shows the characteristic of “adverse wind area,” while the weak storm shows the characteristic of mesocyclones. The direction turning of radar echoes is also studied and the analysis shows that radar echoes turned to the area with greater hail diameter the rotational velocity in the mesocyclone.