【摘要】 利用石家庄CINRAD/SA型多普勒雷达站的VAD产品的风向、风速、VWP产品,以及通过EVAD技术计算绘制的散度、垂直速度分布廓线,对石家庄雷达站35 km内,在2004—2005年出现的4次冰雹天气过程出现前后1 h左右的环境条件进行了分析。结果表明:冰雹发生时,在3~6 km的回波中层主要为偏西风、偏北风,随高度上升风速显著增加,在6~9 km风速达到最大;在冰雹发生前VWP产品上高低层有较强的垂直风切变,风向随高度顺转;高空急流下传与冰雹的发生密切相关;在冰雹过程发生前后3~6km存在明显的由上升运动到下沉运动的转变。为准确监测、预报冰雹天气提供依据。更多还原

【Abstract】 In order to forecast hail rightly we used the VWP products,wind direction and wind velocity of VAD products supplied by CINRAD/SA Doppler weather radar in Shijiazhuang,and drawed the profile through calculating divergence and vertical velocity by EVAD method.The environment condition that before and after 1 hour when the 4 times hail happened in the area of 35 km around Shijiazhuang Doppler Radar station from 2004 to 2005 were analyzed in this article.The result show as the follows: Most of the wind direction of hail is western or northern at 3—6 km level of the echo.There is a distinct increase of wind speed at the height of 3—6 km,and it became the biggest at the height of 6—9 km.There is strong vertical wind shear between the high and low level.The occurrence of hail relates closely with the downward perturbation of the high level jet.There is raising movement before hail and sinking movement after hail at the height of 3—6 km.We provided reference for the forecast of severe convection.更多还原