Causation Analysis of a Short-Time Strong Rainfall Triggered by Cold Front at the Northern Piedmont of Qinling Mountains

  • WANG Nan ,
  • ZHAO Qiang ,
  • JING Yu ,
  • ZHANG Xiaowen
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  • Shaanxi Meteorological Observatory, Xi'an 710014, shaanxi, China;National Meteorological Centre, Beijing 100081, China

Received date: 2017-06-21

  Online published: 2018-10-28

Abstract

On August 3, 2015, a short time heavy rainfall suddenly occurred at the northern piedmont of Qinling Mountains, whose intensity has been rarely seen in recent years, triggered floods and caused casualties.Based on the analysis of aerological sounding data, intense surface observation data, NCEP reanalysis data, wind profile data and Doppler radar data, it was found that the precipitation process has good convective potential and humidity condition, and it was triggered by the cold front system.The structural features of the cold front system include:thewater vapor content was greater than 18 g·kg-1 near surface in front of the front zone, the frontal rising motion located above the sinking movement and below the free convection level, there was significant convection instability ahead of the front and so on, which are all favorable conditions for the occurrence of convective strong precipitation.The calculation result of frontogenetical function showed that strong frontogenesis(up to 20×10-10 K·s-1·m-1) of this process mainly occured in the middle and lower troposphere.The main reason is that the cold front system was accompanied by strong cold advection at 850 hPa which caused the horizontal frontogenesis; convective instability and the ascending motion caused vertical frontogenesis.In addition, the strong cold advection at 850 hPa caused shallow temperature inversion of the layer, so that convective instability energy can be concentrated, that is another favorable factor for the development of strong convection in the afternoon.The wind shifted to the west and formed ultra low level strong westerly wind with feedback of heavy rainfall after the cold front passed due to the blockage of Qinling Mountains.The westerly winds combining with the windward slope of Qinling Mountains made amplitude effect to the precipitation and brought low level water vapour transportation for the precipitation area, but the presence of the ultra low westerly wind causes the environment wind appeared negative vertical wind shear and was consistent with the moving direction of the storm.Under the influence of such wind field, the bottom of the storm which has just been established moving eastward faster than the top, and the vertical structure of the storm is difficult to maintain for a long time.The wind profile radar can detect the fine vertical wind structure of the cold front system, which reflects the vertical structure information of the cold front and predict weather system development much earlier than the other meteorological elements, which has a good indicative significance for the forecast.

Cite this article

WANG Nan , ZHAO Qiang , JING Yu , ZHANG Xiaowen . Causation Analysis of a Short-Time Strong Rainfall Triggered by Cold Front at the Northern Piedmont of Qinling Mountains[J]. Plateau Meteorology, 2018 , 37(5) : 1277 -1288 . DOI: 10.7522/j.issn.1000-0534.2017.00070

References

[1]Bai X P, Wang S G, Zhao L, et al, 2016.Conceptual models of short-time heavy rainfall in the east of Northwest China[J].Plateau Meteor, 35(5):1248-1256.DOI:10.7522/j.issn.1000-0534.2015.00102.<br/>白晓平, 王式功, 赵璐, 等, 2016.西北地区东部短时强降水概念模型[J].高原气象, 35(5):1248-1256.
[2]Chang Y, Li X J, Chen C, et al, 2016.Mesoscale characteristics of a rainstorm process in inner mongolia and its cause analysis[J].Plateau Meteor, 35(2):432-443.DOI:10.7522/j.issn.1000-0534.2014.00155.<br/>常煜, 李秀娟, 陈超, 等, 2016.内蒙古一次暴雨过程中尺度特征及成因分析[J].高原气象, 35(2):432-443.
[3]Chen M, Tao Z Y, Zheng Y G, et al, 2007.The front-related vertical circulation occurring in the pre-flooding season in South China and its interaction with MCS[J].Acta Meteor Sinica, 65(5):785-791.<br/>陈敏, 陶祖钰, 郑永光, 等, 2007.华南前汛期锋面垂直环流及其与中尺度对流系统的相互作用[J].气象学报, 65(5):785-791.
[4]Chen T, Dai K, Zhang F H, 2013.Study on ambient condition and initialization mechanism of convection in a severe squall line storm event in North China[J].Meteor Mon, 39(8):945-954.<br/>陈涛, 代刊, 张芳华, 2013.一次华北飑线天气过程中环境条件与对流发展机制研究[J].气象, 39(8):945-954.
[5]Gu H P, Ma S Q, Wang Y C, et al, 2008.Application of Airda-3000 boundary wind profile radar in analyzing summer heavy rainfall in Beijing[J].Meteor Sci Technol, 26(3):300-304.<br/>古红萍, 马舒庆, 王迎春, 等, 2008.边界层风廓线雷达资料在北京夏季强降水天气分析中的应用[J].气象科技, 26(3):300-304.
[6]Guo Y L, Wang J Z, Li C Y, et al, 2014.Effect of frontogenesis on rainstorm in Hubei During Meiyu Period 2011[J].Meteor Mon, 40(1):86-93.<br/>郭英莲, 王继竹, 李才媛, 2014.锋生作用对2011年梅汛期湖北暴雨的影响[J].气象, 40(1):86-93.
[7]Lu X N, 2017.Potential trend, trigger and evolution analysis of a thunderstorm case in Henan[J].Plateau Meteor, 36(1):195-206.DOI:10.7522/j.issn.1000-0534.2016.00023.<br/>吕晓娜, 2017.河南一次强对流天气潜势、触发与演变分析[J].高原气象, 36(1):195-206.
[8]Qu X B, Zhang T, Liu X H, et al, 2010.Analysis on the meterological causes for the 8 August 2010 massive mudslide in Zhouqu, Gansu province[J].Meteor Mon, 36(10):102-105.<br/>曲晓波, 张涛, 刘鑫华, 等, 2010.舟曲"8·8"特大山洪泥石流灾害气象成因分析[J].气象, 36(10):102-105.
[9]Sun J S, 2005.A study of the basic features and mechanism of boundary layer jet in Beijing Area[J].Chinese J Atmos Sci, 29(3):445-452.<br/>孙继松, 2005.北京地区夏季边界层急流的基本特征及形成机理研究[J].大气科学, 29(3):445-452.
[10]Sun J S, Tao Z Y, 2012.Some essential issues connected with severe convective weather analysis and forecast[J].Meteor Mon, 38(2):164-173.<br/>孙继松, 陶祖钰, 2012.强对流天气分析与预报中的若干基本问题[J].气象, 38(2):164-173.
[11]Sun J H, Zhao S X, Fu S M, et al, 2013.Multi-scale characteristics of record heavy rainfall over Beijing area on July 21, 2012[J].Chinese J Atmos Sci, 37(3):705-718.<br/>孙建华, 赵思雄, 傅慎明, 等, 2013.2012年7月21日北京特大暴雨的多尺度特征[J].大气科学, 37(3):705-718.
[12]Tao S Y, Wei J, Zhang X L, 2008.Large-scale features of the mei-yu front associated with heavy rainfall in 2007[J].Meteor Mon, 34(4)3-15.<br/>陶诗言, 卫捷, 张小玲, 2008.2007年梅雨锋降雨的大尺度特征分析[J].气象, 34(4)3-15.
[13]Wang J Y, Cui C G, Wang X F, et al, 2014.Analysisis on water vapor transport and budget of the severe torrential rain over Beijing region on 21 July 2012[J].Meteor Mon, 40(2):133-145.<br/>王婧羽, 崔春光, 王晓芳, 等, 2014.2012年7月21日北京特大暴雨过程的水汽输送特征[J].气象, 40(2):133-145.
[14]Wang N, Li P Y, Jing Y, et al, 2016.Mesoscale analysis of a heavy rainfall supercell storm on the Loess Plateau[J].J Meteor Sci, 36(6):742-751.<br/>王楠, 李萍云, 井宇, 等, 2016.黄土高原一次超级单体短时强降水中尺度分析[J].气象科学, 36(6):742-751.
[15]Xu J, Bi B G, Shen Y, 2010.Analysis on mesoscale mechanism of heavy rainstorm in Jinan on 18 July 2007[J].Plateau Meteor, 29(5):1218-1229.<br/>徐珺, 毕宝贵, 谌芸, 2010.济南7·18大暴雨中尺度分析研究[J].高原气象, 29(5):1218-1229.
[16]Xu D B, Gou W, Xiao W, et al, 2018.Case study on the formation mechanism of two types of short-term strong rainfall occurred in Gansu Province[J].Plateau Meteor, 37(2):524-534.DOI:10.7522/j.issn.1000-0534.2017.00056.<br/>许东蓓, 苟尚, 肖玮, 等, 2018.两种类型短时强降水形成机理对比分析-以甘肃两次短时强降水过程为例[J].高原气象, 37(2):524-534.
[17]Yu X D, 2012.Investigation of Beijing extreme flooding event on 21 July 2012[J].Meteor Mon, 38(11):1313-1329.<br/>俞小鼎, 2012.2012年7月21日北京特大暴雨成因分析[J].气象, 38(11):1313-1329.
[18]Yu X D, 2013.Nowcasting thinking and method of flash heavy rain[J].Torrential Rain Disaster, 32(3):202-209.<br/>俞小鼎, 2013.短时强降水临近预报的思路与方法[J].暴雨灾害, 32(3):202-209.
[19]Zhang A C, 2000.Modern meteorological observation[M].Beijing:Peking University Press, 289-298.<br/>张霭琛, 2000.现代气象观测[M].北京:北京大学出版社, 289-298.
[20]Zhang X L, Zhang T, Liu X H, et al, 2010.Mesoscale weather chart analysis techinique[J].Meteor Mon, 36(7):143-150.<br/>张小玲, 张涛, 刘鑫华, 等, 2010.中尺度天气的高空地面综合图分析[J].气象, 36(7):143-150.
[21]Zhao Q, Wang J P, Wang N, et al, 2017a.Diagnostic study of topographic effect of a rainstorm in Qinba mountain in summer in 2012[J].Meteor Sci Technol, 45(1):139-147.<br/>赵强, 王建鹏, 王楠, 等, 2017a.2012年夏季秦巴山区暴雨过程的地形作用诊断[J].气象科技, 45(1):139-147.
[22]Zhao Q, Wang N, Li P Y, et al, 2017b.Diagnosis and analysis of thermal and dynamic mechanism of two rainstorm processes in northern Shaanxi[J].J Appl Meteor Sci, (3):340-356.<br/>赵强, 王楠, 李萍云, 等, 2017b.两次陕北暴雨过程热力动力机制诊断[J].应用气象学报, (3):340-356.
[23]Zhao Y C, Cui C G, 2010.A study of rainstorm process triggering Zhouqu extremely mudslide on 8 August 2010[J].Torrential Rain Disaster, 29(3):289-295.<br/>赵玉春, 崔春光, 2010.2010年8月8日舟曲特大泥石流暴雨天气过程成因分析[J].暴雨灾害, 29(3):289-295.
[24]Zheng J, Sun S Q, Xu A H, et al, 2015.Mechanism of formation and maintenance for a torrential rain on strong meiyu front[J].Plateau Meteor, 34(4):1084-1094.DOI:10.7522/j.issn.1000-0534.2014.00019.<br/>郑婧, 孙素琴, 许爱华, 等, 2015.强锋区结构的梅雨锋短时暴雨形成和维持机[J].高原气象, 34(4):1084-1094.
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