Abstract:Based on the conventional radiosonde rainfall data from 2004 to 2011 of the northern Zhejiang and 2011 NCEP/NCAR reanalysis data, analyzed are the statistic Characteristics of low level jets and their relationship with heavy rain events. The results show that the south west low level jet at 700 hPa appeared most frequently; the frequency decreased with altitude, and there was significant diurnal variation, strengthening in the morning and weakening in the evening; in different types of low level jets, SJ DJU, and TJ occurred relatively frequently. There were nearly 90% rainstorms over the northern Zhejiang in Meiyu season accompanied with low level jets, most of which were the DJU type. The night rainstorms were more closely related to low level jets, compared with daytime rainstorms, and low level jets occur usually 12 h before the happening of the night storms. The heavy rain process in mid June 2011 corresponded to two enhancing processes of the south west low level jet, with the maximum wind speed at 600 hPa and stretching down to the lower levels.