The extra rainfall was mainly due to an active trough of low pressure over the south china coast in may , the combined effect of an active southwesterly and severe tropical storm bilis in july and a tropical depression in september 本年雨量较多主要是五月时受到华南沿岸的一道活跃低压槽影响，七月时受到一股活跃西南季候风与强烈热带风暴碧利斯的共同影响及九月时受到一个热带低气压影响所致。
The active southwesterly winds associated with the remnant of kammuri brought heavy rain and thunderstorms to hong kong on 6 august . the amber rainstorm warning signal was issued at 6 . 10 a . m . and more than 200 millimetres of rainfall were recorded over kwai chung and sha tin on that day 八月六日，与北冕残馀相关的活跃西南风为本港带来大雨和雷暴，天文台在早上6时10分发出了?色暴雨警告信号，当日在葵涌和沙田均录得超过200毫米的雨量。
The most obvious feature of the first leading term of eof applied to the climatic vertically integrated water vapor flux over asian - australian monsoon region shows a planetary - scale southwesterly moisture transport , starting from south hemisphere , passing over asian monsoon region and flowing into north pacific , which indicates the interaction between the northern and southern hemisphere as well as between mid and low latitudes in the northern hemisphere ( 3 )亚澳季风区气候平均状态下4 - 9月份的水汽通量的eof矢量展开的第一特征向量最显著的特征是存在一条行星尺度的强西南风水汽输送带，它源于南半球低纬地区，经过亚洲季风区，进入北太平洋地区，集中反映了南北半球和中低纬各支水汽输送气流的相互作用。
The analysis of the large - scale synoptic situation shows that strong precipitation is closely related to the explosion of monsoon and the intensification of cross - equatorial flow which bring a lot of vapor and meet with cold masses at the eastern of northwest district on 8th , june causing extremely heavy rainfall ; that subtropical high - level jet at 200hpa , subtropical high at 500hpa and low - level jet at 850hpa are the weather backgrounds favorable to strong precipitation ; that the pattern of eastern highs and western lows and the establishment of a low - level jet and the coupling between upper - and low - level patterns that determine that the rain occurred in the east of the northwest china ( on average , this is the rainy season for the south of china , but not for the northwest china ) ; that water vapor comes from southerly and easterly flow which converge at the eastern of northwest district with convergence mainly in lower levels and pbl ; that the high value of the whole - level apparent heat source < q1 > is near the area of large rainfall in the direction of northeasterly - southwesterly agreeable to shear line very well and the condensation latent heat releasing is main heat source with vertical advection item playing key role in q1 and q2 ; that there is a vertical secondary circulation crossing low - lever jet whose ascending branch is at the area of large rainfall ; that the construction of convection instability and conditional symmetry instability results that there is not only deep thermal instability , but also moisture influx and triggering mechanism of thermal instability causing strong torrential rain 作为对比，本文还对2002年6月24 - 25日发生在北京地区的强地形雨进行了分析，并讨论陕南、北京地区两地暴雨的异同点以及地形作用的共性和个性，为两地暴雨预报提供有益的参考，得出了一些很有意义的结果： 1大尺度环流背景分析表明： ( 1 ) “ 02 . 6 ”强降水与6月上旬越赤道气流和季风爆发密切相关，携带大量水汽的偏南气流与冷空气于6月8日交汇在西北地区东部，导致了这次强降水的发生； ( 2 ) 200hpa的副热带西风急流、 500hpa副高以及850hpa的低空急流的配置非常有利于本文分析之陕西强降水的发展与维持。大尺度形势分析表明，东高西低形势场、低空急流的建立和高低空形势的配置决定了这场降雨出现在西北地区东部。与暴雨区相联系，存在一支横越低空急流的经向垂直环流，暴雨区处于该垂直环流的上升支； ( 3 )偏南和偏东气流水汽通道在西北地区东部交汇，水汽的辐合积聚主要在对流层低层和行星边界层内完成； ( 4 )整层的视热源< q _ 1 >高值区在暴雨区附近呈东北-西南向分布，与切变线走向非常一致，降水产生的凝结潜热释放是强降水区大气的主要热源。
When the southwesterly ( northeasterly ) moisture flux over southern china and its vicinity increased , then more ( less ) water vapor was transported from the low latitudes to the atmosphere over southern china , which resulted in strong ( weak ) atmospheric moisture sinks over the above - regions in southern china 华南中东部以及广西北音队湖南西部贵州东部地区水汽汇的强度异常与东亚上空水汽输送异常导致上述地区垂直积分的水汽通量辐合的异常密切相关，当中国南方上空有西南（东北）风水汽通量距平，即西南风水汽输送增强（减弱）时，则上述地区上空的水汽汇偏强（偏弱） 。
The above analysis showed that this heavy rainfall event took on obvious meso - scale characters and was the combination of the three flows , so we can deduce : ( 1 ) surface southeasterly wind and topography may play the main role in this event ; ( 2 ) the easterly cold air rushing into the southern shaanxi province in the lower troposphere was strongly relative to the form of surface cold - front type of occlusion ; ( 3 ) there were two reasons for the secondary circulation ' s strengthen in the evening , one was the effect of a mountain - valley wind and the other may be latent heat leading to ascending motion ; ( 4 ) the shape of potential instability stratification corresponded well with the development of the warm - moisture advection ; and ( 5 ) the vapor providing essential thermodynamics was transported by a southwesterly low - level jet from the bay of bengal and the south china sea . furthermore , with the effect of terrain , the southern shaanxi province became the center of this extremely heavy rain process 中尺度结构分析表明，本次暴雨具有明显的中尺度特征，是由三支气流共同作用的结果，分析发现( 1 )地面东南风和地形在这次大暴雨过程起主要作用； ( 2 )东路冷空气主要是通过中低层侵入陕南地区的，并与地面冷式锢囚锋的形成密不可分； ( 3 )夜博士论文:中尺度地形对陕南暴雨的影响研究间垂直次级环流发展加强可能有两个原因，一个是由于地形山谷风的作用，另一个是降水的潜热释放激发了上升运动: ( 4 )位势不稳定层结的形成与低层暖湿平流的发展有很好的对应关系; ( 5 )本次暴雨的水汽主要靠偏南风急流将孟加拉湾和中国南海的水汽输送至西北地区东部，为暴雨的发生提供了必要热力条件。
