摘要
利用常规地面和高空实况、雷达、卫星资料,对2014年6月2日川东北出现的短时强降水和大风天气进行了分析,结果表明:1)该次强对流天气发生在高能高湿大气环境中,500 h Pa冷槽、850h Pa切变及偏东气流、地面中尺度辐合流场共同影响是该次强对流天气发生的主要原因。2)该次强对流天气是发生在由低层偏南风和高层西北风形成的垂直风切变逐渐演变成为由低层偏南风和高层西风形成的垂直风切变,垂直风切变逐渐加强(始终为弱的垂直风切变)的过程中。3)对于初始对流和后续激发对流,地面辐合线的走向与强对流天气的落区、移动基本吻合。4)卫星和雷达在临近预报方面有很好的参考,例如强对流天气发生前,MCS对流云团为线状,雷达回波强度大,反射率因子核随高度迅速下降,0.5°和1.5°仰角径向速度图都出现了速度辐合。
Using conventional surface and upper-level observations, radar and satellite data, we studied a short-range severe rain and strong wind that occurred in the northeastern part of Sichuan province 2 June 2014. The result is shown as follows. 1 ） Taking place in an atmospheric environment that was high in both energy and humidity, the weather was caused jointly by a 500-hPa cold trough, an 850-hPa shear, an east- erly airflow and a mesoscale surface convergent flow field. 2） The weather happened as a mildly strengthe- ning shear of vertical wind, formed by a low-level southerly and an upper-level northwesterly, was gradually transforming into one that consisted of a low-level southerly and an upper-level westerly. 3 ） For the initial convection and subsequently triggered convection, the alignment of a surface convergence line was basically in agreement with the location and movement of the weather. 4） The satellite and radar proved to be good guidance in nowcasting. For instance, prior to the weather, an MCS convective cluster was line-shaped with large radar echoes, rapidly falling reflectivity with height and converging radial velocity at the elevation an- gles of 0.5° and 1.5°.
出处
《广东气象》
2016年第1期36-39,43,共5页
Guangdong Meteorology
基金
2015年中国气象局预报员专项(CMAYBY2015-063)
关键词
天气学
短时强降水
大风
中尺度分析
冷平流
盛夏
川东北
synoptics
severe convection
mesoscale analysis
prime summer
northeastern Sichuan province
