Based on routine weather materials and T213 numerical prediction product , the main influence system and the physic
quantities prediction field related to T213 numerical forecast of the first soaking rain process which occurred on May 5 to 6 in 2003 i
Ningxia were analyzed in this paper. The results show that T213 has excellent prediction ability and direction sense to the precipita
tion in Ningxia, and its credibility is improving constantly with shortening of the forecast prescription.

Anumerical simulation of a torrent rain on July 31 in 2003 in Guyuan was conducted with MM5 and results show that：themodel simulated the effecting systems and the evolution of this weather event，and revealed the meso-scale systems that were undetected by conventional observation.The derived element such as helicity，symmetricinstable index，moistureentropy，ageostrophicmoisture Q vector are capable to indicate the severe convection