Configurations of the East Asian jet stream for extreme precipitation in central eastern China during June

The occurrence of extreme precipitation (EP) is closely associated with atmospheric circulation patterns. Present study documents the configuration of the East Asian jet stream corresponding to EP in central eastern China during June. The analysis is conducted for two sub-regions (26.5º–28.5ºN and 28.5º–30.5ºN within 116º–119.5ºE, denoted as the south and north region, respectively) separately. The two sub-regions have high frequency but distinct year-to-year variations of EP days. The preferred configuration of the East Asian jet stream differs for EP in the two sub-regions. The latitudinal shift of the East Asian jet stream accounts for most EP in the south region, while the intensification of the East Asian jet stream is the dominant configuration for EP in the north region. The changes in the location and intensity of the East Asian jet stream are associated with meridional wave patterns along East Asia and zonal wave patterns over mid-latitude Eurasia. The role of the western North Pacific subtropical high is robust but relatively larger for EP in the south region. The South Asian high plays an important role for EP in the south region, but its role is weak for EP in the north region. Wind-induced temperature anomalies modulate the vertical change of the meridional height gradient over eastern China and thus contributes to the latitudinal shift and intensity change of the East Asian jet stream. The present study suggests a strong dependence upon the EP region of atmospheric circulation systems that cause EP in central eastern China during June.