广东省二次首场暴雨过程的特征分析

Analysis of the Characteristics of Two Annually First Torrential Rains in Guangdong Province

使用地面逐小时加密观测资料、6 h间隔的NCEP(水平分辨率1°×1°)的fnl全球再分析资料、micaps观测资料,通过分析2011年和2012年广东省2次首场暴雨过程的环流形势、水汽条件、热力条件、动力条件,得到以下结论:2次过程一次为持续性弱降水导致暴雨;一次是短时强降水导致暴雨。2次暴雨过程均受南支槽前和副高西北侧西南气流影响;2次过程均有比较好的水汽条件,但水汽辐合存在强弱和持续程度不同的区别;2次暴雨过程的暴雨区850 h Pa均处在θWse高值区的下游,"110318"暴雨过程开始前和开始后均没有出现CAPE值,而"120304"过程气块从850 h Pa抬升则出现CAPE;2次过程上升气流也存在持续性和强弱的区别。

Based on hourly intensively observed surface data, 6 -h -interval NCEP reanalysis （with horizontal resolution of 1 ° 1 ° ） and MICAPS data, the circulation pattern and the conditions of water vapor, thermodynamics and dynamics are studied of two annually first torrential rains that took place in Guangdong province in 2011 and 2012. Conclusions are drawn as follows. The two torrential rains were caused by per- sistently weak rain and short - range intense rain, respectively. Both subject to the effect of southwesterly airflows in front of a southern branch of the westerlies and off the northwest side of the subtropical high and both fed with the right water- vapor conditions, the two rains differed in the intensity and duration of water - vapor convergence. During the process, both the rain areas were downstream of a zone of high ＆ values. While the rain in 2011 did not have CAPE values before and after the initial moment of the process, the rain in 2012 witnessed the appearance of CAPE as air parcels were being lifted from the level of 850 hPa. The as- cending air currents of the two rains also differed in persistence and intensity.