摘要
利用常规MICAPS数据资料,对广西"回南天"发生特征及预报着眼点进行分析研究。结果表明:(1)"回南天"发生在春季低温阴雨后期迅速回暖的转变过程中;(2)有利"回南天"发生的环流形势共同特征为:500 hPa我国北支西风气流转为纬向环流,南支槽加深并向东移动,850 hPa有西南急流,地面冷空气减弱,华南静止锋减弱北抬;(3)T-lnp探空曲线中,锋区逆温层上限持续下降到850 hPa以下,次日落地消失;(4)室外空气露点温度高于室内物体表面温度,暖湿空气中的水汽入室遇冷后,在物体表面发生相变凝结;(5)根据前一天最低气温、当天露点温度及升幅,将"回南天"划分为重度、中度和轻度3个等级;(6)"回南天"有冷性结束和暖性结束两种方式。所得成果可应用到预报业务中。
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.
出处
《气象》
CSCD
北大核心
2015年第3期372-379,共8页
Meteorological Monthly
基金
中国气象局华南区域气象中心科技攻关项目(GRMC2012M08)
桂科攻(10123009-8)共同资助
关键词
回南天
发生特征
成因分析
预报着眼点
广西
continuous wet weather
synoptic features
cause analysis
forecast method
Guangxi
