1911号台风“白鹿”过程的诊断分析

Diagnostic Analysis of the Life Cycle of Typhoon Bailu (1911)

为台风过程预报服务提供参考,利用美国国家环境预报中心(NCEP)再分析资料、汕头区域自动站逐时资料和联合台风警报中心(JTWC)卫星云图等资料,综合分析1911号台风“白鹿”的环流背景和影响,并对其的发生发展和影响过程物理量特征进行诊断分析。结果表明:(1)“白鹿”是在副高偏强且稳定的环流背景下发生的,台风路径为稳定西北向,降水分布南多北少;(2)“白鹿”从生成到停编,结构都存在明显的不对称性;(3)高层辐散低层辐合的流场配置有利于上升运动的建立和维持,配合持续较长时间的不稳定层结及低层高温、高湿、高能的有利条件,为该次降水提供了有利条件。

Using the reanalysis of the National Centers for Environmental Prediction(NCEP), hourly data from the regional automatic weather stations in Shantou and the weather satellite cloud imagery from the Joint Typhoon Warning Center(JTWC), this work makes a comprehensive analysis of the circulation background and effects for Typhoon Bailu(coded 1911) and a diagnostic analysis of the characteristics of its physical quantities during the genesis, development and the impacts it imposed. The results are shown as follows.(1) Generated under the circulation background of a strong and stable subtropical high, Bailu took a steady route of moving to the northwest and brought about precipitation that distributed more in the south than in the north.(2) For its life cycle from the genesis to the time when it was decoded, Bailu’s structure was much asymmetric.(3) The allocation of the associated flow field with upper-level divergence versus low-level convergence helped the ascending motion establish and maintain, and the precipitation Bailu caused was attributed to unstable stratification that persisted over an extended time and a very warm and humid and full-of-energy low level.