Abstract: Two local short-term heavy rainstorm occurred in Yulin on 8 and 10 August（hereinafter referred to as process I and process II）are with the accumulated rainfalls of 103.4 mm and 142.5 mm respectively.Based on data of NCEP reanalysis,automatic observation,FY-2 E satellite and Doppler radar,background circulation and mesoscale characteristics of two process are analyzed in this paper.The results show that:（1）Strong convective weather process I is triggered by short-wave trough in the northwest of subtropical high.Development and integration of small convective cells triggered by surface convergence lines and lead to thunderstorm,causing accumulation of cold pools on the ground.As a result,surface temperature and pressure are inversely proportional to each other.Moreover,short-term strong precipitation is corresponding to areas with low TBB,and extreme hourly precipitation caused by mesoscale-γ severe convective clouds are responsible for short-term heavy rain.（2）Process II is caused by cold air produced by northeast cold vortex moving south,and development of strong convection is less weaker than that of process I,so there is no thunderstorm high,making a positive correlation between surface temperature and pressure.In satellite images,short-term strong precipitation is corresponding to the areas with large gradient of TBB,and convective clouds on the upstream region of Shenmu county moving to east and developing continuously,producing longer “the train effect”and resulting in local short-time heavy rainstorm in Shenmu.