Analysis and forecasting of heavy-rainfall event by strong convection

作者：Ran Ling-Kun^*; Zhou Yu-Shu; Yang Wen-Xia

来源：Acta Physica Sinica, 2011, 60(9): 099201.

• vertical component of convective vorticity vector
• moist thermodynamic advection parameters
• wave-activity density

For the case of severe convection occurring in the southern region of North China on July 8, 2009, the three dynamical factors, namely, vertical component of convective vorticity vector, moist thermodynamic advection parameter and wave-activity density are diagnosed. The result shows that the anomalous-value regions of dynamical factors are located mainly in middle and lower troposphere over the strong precipitation area. Since the dynamical factors can effectively describe the synthetical characteristics of strong convective system, such as vertical shear of horizontal wind, advection of potential temperature, vorticity perturbation and baroclinicity of moist atmosphere, they correspond to the observation of 6-h accumulative rainfall in horizontal distribution patterns.
Using the 6-h, 12-h, 18-h and 24-h forecasting dataset of U. S. NCEP/NCAR 0.5-Degree GFS, the dynamical factors are calculated to analyze their indications of precipitation forecasting during a longer period. The results show that during June 2 - Oct 1, 2009, the 6-h, 12-h, 18-h and 24-h forecasted dynamical factors each have an indication of strong precipitation. The moist thermodynamic advection parameter suggests that the precipitation is best among the three dynamical factors.

• 出版日期2011-9
• 单位中国科学院大气物理研究所