【摘要】 2009年3月黑龙江省频繁出现雨雪天气,本文利用NCEP再分析资料,对其成因进行了初步分析。研究表明:本次过程发生在大气环流异常的背景下:极涡面积大、强度强;欧亚中高纬地区呈两脊一槽;蒙古气旋较为活跃。低空急流输送水汽和低层上升运动是增强降雪强度的有利条件,这一分析结果对预报暴雪天气具有指示意义。更多还原

【Abstract】 strong rain and snow process happened in HeiLongJiang Province in March 2009 were analyzed based on NCEP reanalysis data.It shows that longitudinal circulation was very abnormity in the northern hemisphere.The 500 hPa geopetential height field was two ridges and and a trough between them in the middle-high latitudinal Eurasia region.The low level jets and the convergence of wind may be considered as triggering mechanism for the heavy rain and snow.更多还原