Synoptic Features and Forecast Method for Continuous Wet Weather in Guangxi
The features and forecast method are found by analyzing daily MICAPS data. The results indicate that: (1) Continuous wet weather happens in the condition that it warms up rapidly after the continuous cold wet weather. (2) The favorable circulations for the continuous wet weather are that the circulation at 500 hPa turns to zonal in North China, the south branch trough strengthens and moves eastward, southwesterly jet sets up at 850 hPa, the surface cold air weakens and the quasi stationary front moves to north. (3) The top of the front is below 850 hPa in curve T lnp and continuous wet weather may occur on the next day when the front goes down to the surface. (4) The warm and humid air condenses on the cold surface indoors where surface temperature is lower than dew point outdoors. (5) Continuous wet weather can be divided into heavy, moderate and light degrees based on the minimum temperature on the day before, the dew point and the heating extent on the very day. (6) Continuous wet weather has two ending ways: cold ending and warm ending. All the results above can be applied in forecasting operations.