融合多种探测资料的局地分析预报系统(LAPS)能够提供包含中尺度信息的高分辨率中尺度分析场,利用LAPS资料同化分析场分析2009年6月5日发生在江苏徐州的一次冰雹、龙卷强对流天气的中尺度特征。分析结果表明,(1)对流发生时,大气处于不稳定状态。(2)动力不稳定条件,为强对流天气提供了能量;而充足的水汽条件,有利于强对流的维持。(3)低层辐合、高层辐散的配置有利于对流运动的产生和发展。(4)强对流发生时会伴随强烈的上升气流。(5)从可降水量和水成物分布可以很好的识别出降水区和冰雹发生区。应用结果表明,LAPS输出的各种物理量场对强对流天气系统有较好的解释应用能力,能清楚地反映强对流系统的中尺度特征。
Local Analysis Prediction System(LAPS) is a useful tool that employs various observation data to generate meteorological mesoscale 3D information fields with high temporal and spatial resolutions.A strong convective weather,which had been happened in Xuzhou of Jiangsu Province on 5 June,2009,was analyzed with LAPS data.The results indicate as follows:(1) When convection is happening,the atmosphere is in an unstable state.(2) A dynamic and unstable condition is the energy for the strong convective weather;abundant water vapor is of benefit to keep a strong convective state.(3) Both low layers convergence and high level divergence are helpful for the convective motion.(4) Also when convection is happening,updraft is extremely intense.(5) Precipitation distribution can distinguish precipitation area and hailstone area very well.Application results show that LAPS physical quantity fields possess good explanation application ability for a strong convective weather system,and they can clearly reflect the meso-scale characteristic in the strong convective system.By comparing with the observational data,it is found that the physical characteristics of LAPS are consistent with the actual weather conditions,and the LAPS data have many advantages in forecasting the meso-scale convection system.