基于L波段秒级探空数据V-3θ图形的四川盆地暴雨预报模型研究

Forecasting Model of Torrential Rain in Sichuan Basin based on V-3θ Structural Graphs of L-Band Second Level Sounding Data

针对暴雨天气的短期预报难度大的问题,绘制了基于L波段秒级探空的V-3θ图形,应用结构滚流法分析了四川盆地24次大范围的暴雨天气过程,结果表明:暴雨过程前,一般具有低层偏南风、中层西南风、高层偏北风的整层顺滚流特征,湿位温θ_(sed)和饱和位温θ~*相差较小,在中高层200～400 hPa有偏北风和西南风的辐合层,在100～300 hPa有超低温,θ_(sed)和θ~*线与T轴近乎垂直或左倾,大气处于不稳定状态,建立的暴雨短期预报模型效果较好。

Aiming at the difficulty of short-range forecast for heavy rain,the V-3θstructural graph based on L-band second level sounding seconds data is drawn,and the structural roll method is used to analyze 24 large-scale rainstorm weather processes in Sichuan Basin.The results show that before the torrential rain,weather generally has the characteristics of the whole layer rolling flow of the lower south wind,the middle southwestern wind and the upper north wind.The difference between the wet potential temperatureθsed and the saturated potential temperatureθ*is relatively small.There is convergent layer of the north wind and the southwest wind between 200-400 hPa and ultralow temperature layer between 100-300 hPa.Theθsed and lines are perpendicular to the T axis or tilted to the left.In this case,the atmosphere is in an unstable state,the established short-term forecasting model of torrential rain is effective.