Analysis of convective storm rainfall under influence by a distant Typhoon

By using routine observational data, meso-scale weather station data, Doppler radar products, satellite products and NCEP reanalysis data, a heavy rainfall event occurred during October 13 to 14, 2010 in Jiangxi was analyzed in detail. Results are as follows. (1) The rainfall event was caused by the combination of a Typhoon inverted trough and a mid-latitude westerly upper trough. The dynamic lifting was enhanced because the westerly trough is in phase with the inverted trough. Southerly airstream at the east side of Typhoon transports water vapor into the storm zone. (2) Dry and cold air of the upper trough intruded into the warm and wet flow, which enhanced the convective instability.The genesis and development of the depression were favored by the downward transport of potential vortex and low-level abnormal potential temperarure. (3) The negative change of surface pressure formed a meso-scale system which triggered the convection precipitation. (4)There were 3 convective cloud clusters developed along the south side of the energy front. Meso-scale convective cloud clusters moved along the front and were enhanced when passing the high energy center.