Diurnal variation of the duration and environment for heavy rainfall during the warm season in South China

• Main Author: Shui‐xin Zhong
• Format: Article
• Language: English
• Published: Wiley 2020-06-01
• Series: Atmospheric Science Letters
• Subjects: atmosphere; geophysical sphere; observational data analysis; physical phenomenon; rainfall; seasonal scale
• Online Access: https://doi.org/10.1002/asl.969

Abstract This article aims to examine the diurnal variation of heavy rainfall (HR) for various intensities and investigate duration and environment of HR during the warm season over South China. Results show that the HR mainly occurred in the late afternoon over most regions of Guangdong Province (GD) and east of Guangxi Province (GX), as well as the nocturnal‐to‐morning rainfall over the mountainous regions of northwestern GX and contiguous regions among GD. It exhibited two diurnal peaks in the early morning and in the late afternoon. HR which mostly occurred during the late afternoon by 1,700–1,900 LST exhibited longer durations (3–4 hr). The enhanced southerly wind and northerly wind over the mountainous, as well as the enhancement associated with strong horizontal surface‐temperature gradient due to surface heating and stronger vertical wind shear in the lower troposphere, contributed to the high‐frequency occurrences of the rainfall in the late afternoon.