The Synoptically-Influenced Extreme Precipitation Systems over Asian-Australian Monsoon Region Observed by TRMM Precipitation Radar

This study investigates the synoptic-scale flows associated with extreme rainfall systems over Asian–Australian monsoon region (90–160°E and 12°S–27°N). On basis of statistics 17-year Precipitation Radar observations from Tropical Rainfall Measurement Mission, a total 916 systems, both horizontal size maximum intensity exceeding 99.9th percentiles tropical are identified this region. The synoptic wind pattern distribution surrounding each system classified into four major types: vortex, coastal, coastal none above, accounting for 44, 29, 7, 20 %, respectively. vortex type occurs mainly off-equatorial areas in boreal summer. coast-related types show significant seasonal variations their occurrence, high frequency Bay Bengal summer on west side Borneo Sumatra winter. none-of-the-above mostly open ocean winter; these events cold surge events. environment analysis shows that extremes warm season found within where water vapor low-level vertical shear occur frequently. Despite different environments, similar internal structure, broad stratiform wide convective core (WCC) rain. Furthermore, rain rate is located area, near convective–stratiform boundary system. Our results highlight critical role strength direction generation areas. With enhancement moisture by flow, convection triggered diurnally has higher chance to organize mesoscale hence probability produce rainfall.