“96·8”特大暴雨中低层流场的滤波分析

Filter Analysis of the Low Level Stream Field in Torrential Rain Event is Early August 1996

１９９６年８月特大暴雨过程中Ｔ６３模式资料的低层流场进行滤波分析发现：在台风低压的东北象限有一条东北～西南向的辐合线，它的出现是台风低压北上过程中与西风带高压交绥，并相互作用的结果，其生命史与暴雨发生时段相当吻合，是造成“９６·８”暴雨的中尺度系统之一；该辐合线具有东风波的某些结构特征，暴雨区出现于它的东南一侧。

Based on the T63 model data,the torrential rainfall over Hebei province during August 1996 (‘96 8’ event) was analysed by filtering low layer stream field.The results are as follows:within the east north quadrant of Typhoon 9608 low,there was a convergence line whose moving trend was northeast to southwest.It resulted from the interaction of the typhoon low air pressure and the cold air in the westerly wind bnad,while the former was moving northward.Its life period extremely coincided with the heavy rain's,so it was one of the meso scale synthetic system that caused ‘96 8’ event.The convergence line had some features of an easterly wave,and extreme rainfall zone appeared at the east south side of the convergence line.