重庆机场20年初雷特征统计与分析

本文对1991~2010年发生在重庆江北机场的初雷进行了统计分析, 发现初雷多出现在每年的3、4月份, 3月中下旬应是预报员重点关注的时间。初雷大多出现在下午到后半夜, 以前半夜到次日清晨最多。95%的初雷持续时间在2小时以内;初雷的强度总体较弱, 其中干雷和弱雷雨占80%。高空槽是重庆机场产生初雷的主要天气系统, 20次初雷中18次都有它的影响, 高空槽和冷空气共同作用下产生的初雷占55%。雷达平显回波强度在55~60dbz之间, 高显回波顶高基本都在11km以下。初雷在卫星云图上往往容易隐藏于冷锋云系和高空槽云系中, 加之对流性地特征并不明显, 给预报带来一定难度。

Statistics and Analysis on the Characteristics of the First Thunderstorm in Chongqing Airport in 20 Years

Based on the static analysis of first thunderstorms in Chongqing Airport during 1991 -2010,it shows that most of first thunderstorms occur in Mrch and April, and forecasters put more focus on mid - to - late March. They mostly occur from afternoon to after midnight, especially during the half of the night to dawn in next day. 95% of first thunderstorms last less than 2 hours. Their intensity is weak, 80% of them are - TSRA or even only TS. Upper trough is the main synoptic system of gen- erating first thunderstorms, and it occurs 18 times in 20 years. 55% of first thunderstorms are created by upper trough and cold air mass. The radar reflectivity is between 55 -60dbZ in PPI, and the RHI shows that the highest echo is basically under 11 km. In the satellite pictures, it is found that first thunderstorms frequent]y hide in the cloud system of upper trough or cold front. The convective characteristics of first thunderstorms are not obvious , which brings difficulties to forecasters.