摘要
为发挥多普勒天气雷达监测和预警冰雹、雷雨大风、短时强降水等强对流天气的作用,制作出精细化的临近和短时预报,选取了江西8次典型的强对流天气过程,从7个方面对冰雹大风和短时强降水两类强对流天气的多普勒天气雷达回波特征进行对比分析。结果表明:江西省冰雹、雷雨大风过程45~55dBz强回波平均高度为12.4km,达到或超过-25℃层的高度,比短时强降水回波高5.6km。弱回波区(wER)或有界弱回波区(BwER)、三体散射长钉、持续高垂直积分液态水含量、中气旋、下湿上干或强风垂直切变特征等都是冰雹天气的典型特征。而相对平均径向速度图上“S”型暖平流及表现强低空急流的“牛眼”、深厚的湿度层等,则是短时强降水的主要特征,这些特征可为两类强对流天气短时临近预报提供预报参考。
To fully apply Doppler radar data in detecting and warning the convective weather events such as hail, intense gust and short-time heavy rainfall with thunderstorm and high resolution nowcasting, 8 typical events featured by intensive convection are selected for a comparative analysis of the echo features of hail and intense gust and short-time heavy rainfall with the particular emphasis on the differences between the echo features of hail and intense gust and shorttime heavy rainfall from seven aspects. The results show that the average echo height with refiectivity from 45 to 55dBz is 12.5km high when the hail or gust with thunderstorm occurs. It reaches or even exceeds the height of the layer with the temperature of - 25℃ and is 5.6km higher than that of the short - time heavy rainfall. As for hail, the typical echo characters include WER (Weak Echo Region) or BWER (Boundary WER), TBSS (Three-Body Scatter Spider), sustaining high VIL, high humidity in lower layer and low humidity in high layer, mesocyclone and strong vertical wind shear. On the other hand, when the short-time heavy rainfall occurs, the typical echo characters corresponding to Doppler radar products as SRM (storm-relative map) velocity include warm advection S-shaped, low-layer airflow shaped like the eyes of cattle and the thick layer of humidity. Those characters can provide some valuable references to noweasting convective weather of two types of hail and shortly heavy rainfall.
出处
《气象》
CSCD
北大核心
2007年第3期48-53,I0002,I0003,共8页
Meteorological Monthly
基金
江西省科技厅<江西突发性强风暴天气监测和预警研究>
中国气象局预报员专项<江西省强对流天气预警技术研究>
江西省气象局<江西突发性强对流天气预报研究>