ANALYSIS OF THE WEATHER PROCESS OF THE EASTWARD MOVING TROUGHS IN THE SOUTH BRANCH OF WESTERLIES OVER THE CUSHION OF COLD AIR IN SOUTH CHINA IN SPRING

In spring there offen remains a layer of cold air above the ground of the east of the Tibetan Plateau after the invasion of cold air in South China.At this time if a trough in the south branch of the westerlies moves eastward over this cold cushion,then there offen appears a trough and frontogenesis in the region surface high.This paper deals with this type of weather process occurred in South China in the months of March to May of 1958-1962.Further the problem of forecasting the precipitation and the thunderstorm activity occurred in this weather process is discussed.