广西强天气分布特征及物理量诊断分析

【目的】分析研究广西强天气的时空分布特点和变化特征,在天气形势分型的基础上统计提供强天气发生的物理量诊断阈值。【方法】采用长时间序列、大批量样本进行分类统计和合成分析方法。【结果】雷暴南部多,北部少,其中桂东南和沿海地区是雷暴的高发区;冰雹主要出现在北部,桂南降雹少;广西东部和沿海地区为大风频发区;历年龙卷风天气发生次数不多,且集中在涠州岛及沿海地区;强降水呈南北两个高频带。雷暴、降雹和强降水的月变化都具有"单峰型"特征,大风月分布具有"双峰型"特征。强降水主要出现在夜间至次日8∶00,大风、雷暴和冰雹天气则主要出现在午后至傍晚。【结论】广西强天气具有明显的地域分布特征,不同地域及不同天气系统影响下的温度层结和不稳定能量等特征物理量都有较大差异。

Analysis on Characteristics of Spatio-temporal Distribution and Physical Parameters of Severe Weather in Guangxi

[Objective] The characteristics of spatio-temporal distribution of severe weather were analyzed.Base on Synoptic classification,the threshold value of physical parameters for occurrence of severe weather are determined.[Methods] Statistical method and composite analyzing were used in this paper.[Results] Thunderstorm occurs more in south than that in north.The southeast and coastal areas are the frequent thunder areas.Hail occurs more in south than that in north.The eastern and coastal areas are the frequent gale areas.Tornado weather is rare in history,and mainly occurred near the Weizhou Island and coastal areas.The heavy rain mainly occurred in southern and northern areas.The monthly variations of thunderstorms,hail and strong rain all show "single-peak" pattern,but the variations of gale is "double-peak".The heavy rain mainly happened between nighttime to 8 am.The gale,thunderstorms and hail primarily occurred between afternoon to toward evening.[Conclusion] The severe weather in Guangxi has obvious characteristic of regional distribution and the physical parameters,such as temperature stratification and instability energy,show difference in different district and weather system.