Comprehensive Analysis on the Severe Convective Weather Situation Configuration and Its Particularity in Northwest China
By using the precipitation data of the main convective weather processes from the year of 2004 to 2010 in Northwest China,the basic situation configuration of northwest convective weather is divided into three categories by different dominant factors.And,we analyzed the salient features of these three configurations in the field of synoptic-scale environment and the different roles which these features are played in mesoscale convective systems.Meantime,we summarized the main differences among these configurations and also the differences with other regional convective weather configurations.The primary conclusions are as follow:The strong convective weather which is forced by upper air cold advection shows that cold advection may extend downward from 300 hPa to 700 hPa,and 850 hPa is mostly weak warm advection.Compared such kind of convective weather with that occur in the central,eastern of China,temperature lapse rate in the lower troposphere is greater;instability stratification can be stronger in the afternoon;and LFC is higher.Regional convective weather is often associated with ground humidification after large-scale precipitation or low altitude warm air moving northward;local strong convective weather is associated with ground uplift of complex terrain and uneven distribution of water vapor.The strong convection weather which is forced by low level warm advection shows that warm advection plays a dominant role in the lower and wet layer extends from ground upward to near 500 hPa,LFC height is lower significantly.The temperature lapse rate in the lower troposphere is less than the rate in the first situation configuration.The most notable feature of the baroclinic frontogenesis convective weather is the intense interaction between cold and warm air in the lower level,which accompanied with significant temperature frontal zone and frontogenesis.Moisture condition is better than the first situation configuration,vertical wind shear is stronger than the previous two categories significantly.
NETL
NSTL
万方数据
维普
