豫西地区一次春季大风天气分析

利用常规气象资料和多普勒雷达资料，从天气形势、数值预报产品及多普勒雷达产品演变特征等方面，分析了2010年4月26日河南省豫西一次大范围大风天气过程的成因。结果表明，此次大风属于冷锋后的偏北大风，出现在冷锋后高压前沿气压梯度最大的地方，自西向东、自北向南推进；冷锋呈南北向，具有前期移速慢后期移速快的特点；贝加尔湖地区有较强低涡且有强冷中心配合，在两脊一槽的背景下，高空槽为典型的后倾槽，温度槽明显落后于高度槽，中低层温度线与高度线呈近似90。的夹角，利于冷空气的扩散；高低空风向的一致性、风速的差异以及槽后急流带的生成维持和风速辐合带的形成，有利于冷空气下沉，具有显著的动量下传特点，促使锋后地面风速加大出现大风天气；雷达产品为这次大风天气提供了详细的中小尺度临近演变特征，强度产品上出现与大风有关的弱回波带，径向速度图上出现了速度模糊及与大风有关的急流，动量下传作用在不同仰角基本速度的演变特征中得到体现，预示了近地面风速的增大；实况大风出现的时间与〉27rn／s的径向速度区出现的时间比较一致；风廓线图上也较好反映出动量下传作用对地面大风的贡献。

Analysis for a Spring High Wind Weather in Western Henan Province

Using the conventional meteorological observation and Doppler radar data from the weather situation, and the numerical prediction product and Doppler radar products evolution characteristics, the causes of a large - scale wind weather process in Henan Province on Apr. 26, 2010 were analyzed. The results showed that： the cold wind belongs to the north wind, appear in slant cold front air pressure gradient pressure af- ter the biggest place, from the west to the east and from the north to the south advance. A cold front is moving north and south, slow moving first then fast characteristic ; Lake Baikal region has the strong vortex and strong cold center, two ridge within a tank under the background of the up- per, typical of sloping slot, temperature slot greatly behind high slot, low - rise temperature line and highly line is approximate 90 DHS, to an angle of the spread of cold air. High and low empty of consistency and the wind speed of the differences, and after the formation of the rapids slot with maintenance and wind speed, the formation of the coupling with, be helpful for cold air sinking, has the remarkable momentum to transmit characteristics, the wind speed increase after front appeared windy weather. Radar products for the windy weather provides detailed medium and small scale evolution characteristics, strength and related products appear on the winds of the weak echo with radial velocity diagram, appear on fuzzy and wind speed and the rapids, momentum in the different role under the elevation of the basic speed evolution characters are present in the near ground surface and the wind speed increases; The time of appearance and live winds 〉 27 m/s radial velocity area appears consistent with the time ; The wind profile chart also reflects the momentum effect of the ground under the contribution of winds.