Abstract: Based on the daily thunderstorm data and the monthly NCEP/NCAR reanalysis data from 1951 to 2010 in Shantou, the climate characteristics of thunderstorm day and circulation background of thunderstorm day anomaly were analyzed. The results indicate that the thunderstorm day mainly appears from April to September, especially in June. It is in a decreasing trend in recent 60 years, and there is an abrupt change in 1978. The thunderstorm day has multi-scale oscillations, and the main cycle is 25 years. The anomalies of ridge at the Baikal Lake, northern trough, southern trough and subtropical high at 500 hPa result in the abnormal circulation systems of thunderstorm day, and the changes of these systems are contrary in more and fewer years of thunderstorm days. The vapor transportation to Shantou from the subtropical western Pacific and the Bay of Bengal is strong at 850 hPa in more years of thunderstorm days, while it is contrary in fewer years of thunderstorm days.

Key words: thunderstorm days of Shantou, circulation background, Shantou, Thunderstorm day, Climate characteristics, Circulation background