T₆₃₉在新疆阿勒泰地区一次强对流天气中的释用

A Strong Convective Weather Based on T₆₃₉ Mathematical Forecast Products in Altay Area of Xinjiang

摘要: 2012年6月17日午后阿勒泰地区发生一次强对流过程，该过程造成了雷暴、冰雹等强烈天气。该文利用T639数值预报产品对此次强对流天气过程从环流形势、物理量场等方面进行分析。结果表明：低涡减弱东移、中层辐合、底层切变，西南暖湿气流及冷空气的共同影响是造成此次强对流天气的主要原因。T639对700 hPa和850 hPa切变线位置预报非常相似，中小尺度系统为本次天气提供触发机制；T639中水汽输送及辐合条件为本次天气过程提供较好的水汽条件；垂直速度场、涡度场、散度场等预报的指示较好为本次过程提供必要的动力条件；Өse、K指数反应出本次天气较好的能量条件，这些物理量的预报对此次天气过程的发生有较好的指示作用。T639累计雨量预报在量级和落区方面与实况对比有一定的误差。
>One strong convective process occurred in Altay in the afternoon on June 17, 2012. The strong convective weather caused thunderstorms and hailstorms. The conventional weather observations, the data of T639 Mathematical Forecast Products were used to analyze the event. The results indicated that the weakening low vortex and middle-level convergence and low-level wind shear and southwest warm and humid air and cold air were the main reason. Meso-microscale system provided the trigger mechanism. Moisture transport and moist convergence provided the water vapor condition. Vertical velocity and vorticity and divergence provided the dynamical condition. Өse and K index re-flected the energy conditions. The physical quantity field had the well instruction for the weather forecast. T639 accumu-lative rainfall forecast had certain error in magnitude and drop zone.