Traditionally,the
subtropical highs are considered to be dominated by downward motion,not
conducive to precipitation in these areas.But there have been a heavy
precipitation within the subtropical high every few years in Gansu
Province,China.It is very difficult to forecast heavy rainfall inside the
subtropical high.An extreme heavy precipitation process under the control of
the subtropical high occurred in Gansu are analyzed by a variety of
conventional and unconventional observations to study its forming
mechanism.From the prediction results of models,it is found that the large
scale model behaved poorly in predicting this kind of heavy rainfall.Through
the observation data,the overlay of the area of divergence in northeastern
Qinghai-Tibetan Plateau with high pressure and the mesoscale
convergence line near surface layer contributed to form a strong upward
movement,which constituted the weather condition of the heavy
precipitation.Against this background,abundant water vapor,extremely thick warm
clouds,and weak vertical wind shear created a high probability of strong
precipitation.By analyzing various meso-scale observation data,some factors that have
indicative effect in predicting such heavy rainfall have been found as follows:
(1) The maximum gradient of TBB (Temperature of Black-Body) in front of the
movement direction of the cold desk center in the convective cloud cluster was
the place with the strongest precipitation. (2) The strongest precipitation
occurred about 1-2 hours after the total number of lightning reached its peak
and with the lightning places were well positioned. (3) Radar echoes of the
convective bodies which caused heavy rainfall have echo characteristics of warm
cloud precipitation with low mass center. (4) The strongest rain intensity
appeared about 30-40 minutes after the maximums of CR and VIL were reached.
［1］陶诗言.中国之暴雨［M］.北京:科学出版社,1980:35.［TAO Shiyan.Torrential rain in China［M］.Beijing:Science Press,1980:35.］
［2］陶健红,王宝鉴.甘肃省短期天气预报员手册［M］.北京:气象出版社,2012:86.［TAO Jianhong, WANG Baojian.Handbook for short-term weather forecasters in Gansu［M］.Meteorology Press,2012:86.］
［3］白肇烨,徐国昌.中国西北天气［M］.北京:气象出版社,1988:215-216.［BAI Zhaoye,XU Guochang.The weather in the Northwest of China［M］.Beijing:Meteorology Press,1988:215-216.］
［4］吴国雄,丑纪范,刘屹岷,等.副热带高压研究进展及展望［J］.大气科学,2003,27(4):503-517.［WU Guoxiong,CHOU Jifan,Liu Yimin,et al.Review and prospect of the study on the subtropical anticyclone［J］.Chinese Journal of Atmospheric Sciences,2003,27(4):503-517.］
［5］傅云飞,冼桃.副热带高压中心区域内云和降水气候特征研究回顾与展望［J］.暴雨灾害,2017,36(6):489-497.［FU Yunfei, XIAN Tao.Review and prospect of climate characteristics of cloud and precipitation in subtropical high center［J］.Torrential Rain and Disasters,2017,36(6):489-497］
［6］曹美兰,俞燎霓.一次发生在副高内的强对流天气的诊断分析［J］.科技通报,2012,28(1):58-61.［CAO Meilan,YU Liaoni.The diagnosis of severe convective weather occurred in the subtropical high［J］.Bulletin of Science and Technoidgy,2012,28(1):58-61.］
［7］尹红萍,曹晓岗.盛夏上海地区副热带高压型强对流特点分析［J］.气象,2010,36(8):19-25.［YIN Hongping,CAO Xiaogang.Summary on subtropical high severe convection during midsummer in Shanghai area［J］.Meteorological Monthly,2010,36(8):19-25.］
［8］支树林,陈娟,包慧漾.一次副热带高压边缘上大暴雨的中尺度特征分析［J］.气象,2015,41(10):1203-1214.［ZHI Shulin,CHEN Juan,BAO Huiyang.Mesoscale characteristics analysis of rainstorm on the edge of subtropical high［J］.Meteorological Monthly,2015,41(10):1204-1215.］
［9］赵庆云,狄潇泓,张铁军.“8·19”甘肃区域暴雨的特征分析及数值模拟［J］.干旱气象,2005,23(4):12-16.［ZHAO Qingyun,DI Xiaohong,ZHANG Tiejun.Analysis and numerical simulation of the heavy rain in Gansu Province on 19 August 2004［J］.Arid Meteorology,2005,23(4):12-16.］
［10］李如琦,李建刚,王江,等.南疆西部暴雨过程的动力热力结构分析［J］.干旱区地理,2018,41(1):9-16.［LI Ruqi,LI Jiangang,WANG Jiang,et al.Dynamic and thermal structure characteristics of the rainstorms in the west of South Xinjiang［J］.Arid Land Geography,2018,41(1):9-16.］
［11］许东蓓,刘抗,孟丽霞,等.“8.12”甘肃大暴雨特征分析［J］.干旱区地理,2013,36(2):245-252［XU Dongbei,LIU Kang,MENG Lixia,et al.Charactertics of heavy rainfall occurred on 12 August 2010 in Gansu,China［J］.Arid Land Geography,2013,36(2):245-252］
［12］程瑛,黄武斌,沙宏娥.甘肃岷县两次强降水致山洪泥石流灾害特征对比分析［J］.干旱区地理,2018,41(3):443-448.［CHENG Ying,HUANG Wubin,SHA Honger.Cause of two heavy rainfall causing massive mudslide in Minxian County,Gansu Province［J］.Arid Land Geography,2018,41(3):443-448］
［13］付双喜,何金梅.甘肃短时强降水天气若干环境参数特征分析［J］.干旱区地理,2015,38(3):469-477.［FU Shuangxi,HE Jinmei.Shorttime heavy precipitation characteristics of several environmental parameters of Gansu Province［J］.Arid Land Geography,2015,38(3):469-477.］
［14］DOSWELL III C A, BROOKS H E, MADDOX R A.Flash flood forecasring:An ingredients based methodology［J］.Wea Forecasting,1996,11:560-581.
［15］孙军,谌芸,杨舒楠,等.北京721特大暴雨极端性分析及思考(二)极端性降水成因初探及思考［J］.气象,2012,38(10):1267-1277.［SUN Jun,CHEN Yun,YANG Shunan,et al.Analysis and thinking on the extremes of the 21 July 2012 torrential rain in Beijing partⅡ:Preliminary causation analysis and thinking［J］.Meteorological Monthly,2012,38(10):1267-1277.］
［16］方翀,毛冬艳,张小雯,等.2012年7月21日北京地区特大暴雨中尺度对流条件和特征初步分析［J］.气象,2012,38(10):1278-1287.［FANG Chong,MAO Dongyan,ZHANG Xiaowen,et al.Analysis on the mesoscale convective comditions and characteristics of an extreme torrential rain in Beijing on 21 July 2012［J］.Meteorological Monthly,2012,38(10):1278-1287.］
［17］章国材,矫梅燕,李延香,等.现代天气预报技术和方法［M］.北京:气象出版社,2007:103.［ZHANG Guocai,JIAO Meiyan,LI Yanxiang,et al.Modern weather forecast techniques and methods［M］.Beijing:Meteorology Press,2017:103.］
［18］付双喜,安林,康凤琴,等.VIL在识别冰雹云中的应用及估测误差分析［J］.高原气象,2004,23(6):811-815.［FU Shuangxi,AN Lin,KANG Fengqin,et al.Application of VIL in identification of hailstorms and estimation error analysis［J］.Plateau Meteorology,2004,23(6):811-815.］
