Abstract:Based on the data of Intensified Automatic surface Weather observation System (IAWS), ground observation data and sounding data of Shandong Province from June to September from 2009 to 2013, 98 regional heavy rainfall cases are selected, and the synoptic system characteristics of heavy rainfall are statistically analyzed. The synoptic systems at 500 hPa are divided into 6 types, the synoptic systems from 850 hPa to 700 hPa are divided into 5 types, and the surface mesoscale systems are divided into 7 types. The 24 physical quantities representing atmospheric thermal, water vapor and dynamic characteristics during the heavy rainfall and the earlier period are statistically analyzed, and the minimum values, maximum values, mean values, and percentages of threshold values are calculated. The percentages of southerly wind at 850 hPa and 700 hPa that reached jet stream (≥12 m·s-1) are respectively 56.1% and 62.2%. CAPE (Convective Available Potential Energy) equal to or higher than 300 J·kg-1 takes up 72.6%, K index equal to or higher than 30 ℃ takes up 86.7 %, SI (Showalter Index) equal to or lower than 0 takes up 75.5%, θse equal to or higher than 68 ℃ at 925 hPa takes up 82.2%, and θse equal to or higher than 66 ℃ at 850 hPa takes up 74.8%. The precipitable water equal to or more than 55 mm from GPS/MET water vapour monitoring system takes up 81.8%. At 850 hPa and 700 hPa, the mean values of water vapour flux are respectively 8.0 g·(cm·hPa·s)-1 and 5.9 g·(cm·hPa·s)-1, and the mean values of water vapour flux divergence are respectively -4.6×10-9 g·(hPa·cm2·s)-1 and -2.7×10-9 g·(hPa·cm2·s)-1. At 925 hPa, 850 hPa and 700 hPa, the mean values of vorticity are respectively 12.6×10-6 s-1, 12.3×10-6 s-1 and 9×10-6 s-1, and the mean values of divergence are respectively -5.5×10-6 s-1, -3.1×10-6 s-1 and -3.4×10-6 s-1. At 850 hPa, 700 hPa and 500 hPa, the mean vertical velocities are respectively -4.5×10-4 hPa·s-1, -7.4×10-4 hPa·s-1 and -11.1×10-4 hPa·s-1.