Vol.32, NO.5, 2021
Turn off MathJax
Article Contents
Article Navigation >  Journal of Applied Meteorological Science  > 2021  >  32(5): 567-579
Wang Hong, Li Ying, Wen Yongren. Observational characteristics of a hybrid severe convective event in the Sichuan-Tibet Region. J Appl Meteor Sci, 2021, 32(5): 567-579. DOI:  10.11898/1001-7313.20210505.
Citation: Wang Hong, Li Ying, Wen Yongren. Observational characteristics of a hybrid severe convective event in the Sichuan-Tibet Region. J Appl Meteor Sci, 2021, 32(5): 567-579. DOI:  10.11898/1001-7313.20210505.
shu

Observational Characteristics of A Hybrid Severe Convective Event in the Sichuan-Tibet Region

DOI: 10.11898/1001-7313.20210505
  • 1.

    State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081

  • 2.

    Ningbo Meteorological Bureau of Zhejiang Province, Ningbo 351000

  • 3.

    Chinese Academy of Meteorological Sciences, Beijing 100081

  • Received Date: 2021-05-21
  • Rev Recd Date: 2021-07-09
  • Publish Date: 2021-09-30
    Abstract
  • The Sichuan-Tibet Region is a key area for the development of western China, where severe convective weather such as thunderstorm gales occur frequently. However, due to the complex terrains, synoptic systems, and the lack of meteorological observations, it is especially challenging to make accurate prediction. To better understand the mechanism of severe convective weather over the plateau, a rare severe convective event in the Sichuan-Tibet Region on 8 Sep 2016 is analyzed with weather reports, hourly and minutely surface observations, sounding data and Doppler weather radar data from China Meteorological Administration and ERA-Interim 0.5°×0.5° reanalysis data from European Centre for Medium-Range Weather Forecasts (ECMWF). The result shows that hourly rainfall of over 10 mm and hails of over 18 mm are observed at several weather stations, indicating a hybrid moist convective event. The meso-scale convective system (MCS) occurs near a shear line at low level with weak cold advection at 500 hPa. Large environmental convective available potential energy (CAPE), vertical wind shear, and the thick moist atmospheric layer are conductive to the formation of supercell. The initial convection is generated along a surface convergence line, with multiple γ meso-scale cells embedded in stratiform cloud in the north and cluster cells in the south. They move to the southeast, enter the favorable environment and merge with each other, enabling the cell on the south side to quickly develop into a supercell. When the supercell grows matured, the characteristic of front inflow gap, hook echoes and mesoscale cyclone at low levels are clear. The strong echo region tilts forward with height. There is significant overshooting top with the echo top height up to 15 km above ground in the upper troposphere, and obvious echo overhang capping bounded weak-echo region (BWER) in the middle layer. Mid-altitude radial convergence, weakening of updrafts and rapid drop of the reflectivity core indicate the occurrence of downbursts inside the storm. The cooling effect due to the entrainment of midlevel dry air is favorable to the growing of big hails and raindrops, and the formation of downdrafts. Moreover, the drag effect related to the rapid drop of heavy raindrops and hails, and the narrow tube effect of the canyon terrain, contribute to the formation of thunderstorm gales near the ground.
    • FullText(HTML)
    References(38)

  • Fig. 1  Moving paths of strong convection centers(the time interval is 30 min, the black and red lines denote the reflectivity factor ranging from 35-60 dBZ and more than 60 dBZ) from 0500 UTC to 0900 UTC on 8 Sep 2016(a) and probability distribution of hail diameter in the Qinghai-Tibet Region during 2010-2017(b)

    DownLoad: Full-Size Img PowerPoint

    Fig. 2  Geopotential height(the contour, unit:dagpm) and wind at 0000 UTC on 8 Sep 2016

    (the red rectangle denotes convection area)
    (a)500 hPa(the shaded denotes temperature, the brown curve denotes trough), (b)600 hPa(the shaded denotes relative humidity, the brown curve denotes shear line, the grey denotes terrain), (c)200 hPa(the barb denotes upper level jet stream with wind velocity no less than 30 m·s-1, the shaded denotes divergence), (d)surface(the contour denotes sea-level pressure, unit:hPa;the shaded denotes temperature)

    DownLoad: Full-Size Img PowerPoint

    Fig. 3  Environmental convective available potential energy(the shaded) and 500-700 hPa vertical wind shear(the blue contour, unit:m·s-1) on 8 Sep 2016

    (the red rectangle indicates mature supercell area)

    DownLoad: Full-Size Img PowerPoint

    Fig. 4  Radar and surface observations at Ganzi on 8 Sep 2016

    (the dot denotes surface temperature, the number denotes relative humidity(unit:%), the brown curve denotes surface convergence lines, the red ellipse denotes convection positions)

    DownLoad: Full-Size Img PowerPoint

    Fig. 5  Observation at 0.5°elevation angle by Ganzi radar on 8 Sep 2016

    (a)reflectivity factors(the white ellipse denotes hook echo, the white arrow indicates inflow gap), (b)vertical cross-section along line AB in Fig. 5a(the white ellipse denotes echo overhang), (c)reflectivity factors(the white ellipse denotes mesocyclone), (d)vertical cross-section along line AB in Fig. 5c(the white arrow denotes storm inflow direction)

    DownLoad: Full-Size Img PowerPoint

    Fig. 6  Observation at 0.5°elevation angle by Ganzi radar on 8 Sep 2016

    (the white circle denotes mesocyclone, the white arrow denotes supercell inflow direction)

    DownLoad: Full-Size Img PowerPoint

    Fig. 7  Vertical cross-section along line AB in Fig. 6 by Ganzi radar on 8 Sep 2016

    (the red dot denotes Yajiang Station, the white arrow denotes low-level air flow direction)

    DownLoad: Full-Size Img PowerPoint

    Fig. 8  Surface meteorological elements evolution from 0745 UTC to 0825 UTC on 8 Sep 2016

    (a)precipitation(the column) and temperature(the curve) at Yajiang station, (b)pressure(the curve) and wind(the barb)at Yajiang Station, (c)precipitation(the column) at auto weather station 838181, (d)hourly extreme wind(the barb) at auto weather station 838181

    DownLoad: Full-Size Img PowerPoint

    Fig. 9  Topographical sketch map around the stations(a) and 3 h pressure change(the blue contour, unit:hPa) and 24 h temperature change(the shaded) on surface at 0900 UTC 8 Sep 2016(b)

    DownLoad: Full-Size Img PowerPoint
  • [1]
    Duan Y P, Wang D H, Liu Y. Radar analysis and numerical simulation of strong convective weather for "Oriental Star" depression. Journal of Applied Meteorological Science, 2017, 28(6): 666-677. doi:  10.11898/1001-7313.20170603
    [2]
    Song L C. China Meteorological Disaster Yearbook. Beijing: China Meteorological Press, 2017.
    [3]
    Yu X D, Zhang A M, Zheng Y Y, et al. Doppler radar analysis on a series of downburst events. Journal of Applied Meteorological Science, 2006, 17(4): 385-393. doi:  10.3969/j.issn.1001-7313.2006.04.001
    [4]
    Wakimoto R M. The life cycle of thunderstorm gust fronts as viewed with Doppler radar and rawinsonde data. Monthly Weather Review, 1982, 110(8): 1060-1082. doi:  10.1175/1520-0493(1982)110<1060:TLCOTG>2.0.CO;2
    [5]
    Zhang L N, Ran L K, Li N, et al. Analysis of momentum flux and kinetic energy flux transport in the middle and lower troposphere during a thunderstorm event. Chinese Journal of Atmospheric Sciences, 2018, 42(1): 178-191. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201801013.htm
    [6]
    Li G C, Guo W H, Wang L R, et al. Application of gust front to damage wind forecasting. Meteorological Monthly, 2006, 32(8): 36-41. doi:  10.3969/j.issn.1000-0526.2006.08.006
    [7]
    Wu F F, Wang H, Wei Y Y, et al. Analysis of a strong gust front and downburst with Doppler weather radar data. Meteorological Monthly, 2009, 35(1): 55-64. https://www.cnki.com.cn/Article/CJFDTOTAL-QXXX200901010.htm
    [8]
    Bluestein H B. Severe Convective Storms and Tornadoes: Observations and Dynamics. Praxis/Springer, 2013: 120-153. http://link.springer.com/978-3-642-05381-8
    [9]
    Zheng Y G, Zhou K H, Sheng J, et al. Advances in techniques of monitoring, forecasting and warning of severe convective weather. Journal of Applied Meteorological Science, 2015, 26(6): 641-657. doi:  10.11898/1001-7313.20150601
    [10]
    Meng Z Y, Yan D C, Zhang Y J. General features of squall lines in East China. Monthly Weather Review, 2013, 141(5): 1629-1647. doi:  10.1175/MWR-D-12-00208.1
    [11]
    Fujita T T. Tornadoes and downbursts in the context of generalized planetary scales. Journal of Atmospheric Sciences, 1981, 38(8): 1511-1534. doi:  10.1175/1520-0469(1981)038<1511:TADITC>2.0.CO;2
    [12]
    Wang F X, Yu X D, Pei Y J, et al. Radar echo characteristics of thunderstorm gales and forecast key points in Hebei Province. Journal of Applied Meteorological Science, 2016, 27(3): 342-351. doi:  10.11898/1001-7313.20160309
    [13]
    Schoen J M, Ashley W S. A climatology of fatal convective wind events by storm type. Weather and Forecasting, 2011, 26(1): 109-121. doi:  10.1175/2010WAF2222428.1
    [14]
    Klimowski B A, Hjelmfelt M R, Bunkers M J. Radar observations of the early evolution of bow echoes. Weather and Forecasting, 2004, 19(4): 727-734. doi:  10.1175/1520-0434(2004)019<0727:ROOTEE>2.0.CO;2
    [15]
    French A J, Parker M D. Numerical simulations of bow echo formation following a squall line-supercell merger. Monthly Weather Review, 2014, 142(12): 4791-4822. doi:  10.1175/MWR-D-13-00356.1
    [16]
    French A J, Parker M D. Observations of mergers between squall lines and isolated supercell thunderstorms. Weather and Forecasting, 2012, 27(2): 255-278. doi:  10.1175/WAF-D-11-00058.1
    [17]
    Schmidt J M, Cotton W R. A high plains squall line associated with severe surface winds. Journal of Atmospheric Sciences, 1989, 46(3): 281-302. doi:  10.1175/1520-0469(1989)046<0281:AHPSLA>2.0.CO;2
    [18]
    Wang X M, Yu X D, Zhu H. The applicability of NCEP reanalysis data to severe convection environment analysis. Journal of Applied Meteorological Science, 2012, 23(2): 139-146. doi:  10.3969/j.issn.1001-7313.2012.02.002
    [19]
    Ma S P, Wang X M, Yu X D. Environmental parameter characteristics of severe wind with extreme thunderstorm. Journal of Applied Meteorological Science, 2019, 30(3): 292-301. doi:  10.11898/1001-7313.20190304
    [20]
    Wang X M, Zhou X G, Yu X D. Comparative study of environmental characteristics of a windstorm and their impacts on storm structures. Acta Meteorologica Sinica, 2013, 71(5): 839-852. https://www.cnki.com.cn/Article/CJFDTOTAL-QXXB201305004.htm
    [21]
    Chen S Q, Zhang L N, Yu X D, et al. Environmental conditions of three squall lines in the north part of Zhejiang Province. Journal of Applied Meteorological Science, 2017, 28(3): 357-368. doi:  10.11898/1001-7313.20170309
    [22]
    Gao X M, Yu X D, Wang L J, et al. Comparative analysis of two strong convections triggered by sea-breeze front in Shandong Peninsula. Journal of Applied Meteorological Science, 2018, 29(2): 245-256. doi:  10.11898/1001-7313.20180210
    [23]
    Sun J S, Dai J H, He L F, et al. The Principles and Techniques of Severe Convective Weather Forecasting. Beijing: China Meteorological Press, 2014.
    [24]
    Zhang H F, Guo S G, Zhang Y J. Distribution characteristic of severe convective thunderstorm cloud over Qinghai-Xizang Plateau. Plateau Meteorology, 2003, 22(6): 558-564. doi:  10.3321/j.issn:1000-0534.2003.06.005
    [25]
    Zhu P, Yu X D. Analysis of meso-small scale system characteristics of a rare severe convective weather in the northeast part of Qinghai-Tibetan Plateau. Plateau Meteorology, 2019, 38(1): 1-13. https://www.cnki.com.cn/Article/CJFDTOTAL-GYQX201901001.htm
    [26]
    Li J. Hourly station-based precipitation characteristics over the Tibetan Plateau. International Journal of Climatology, 2017, 38(1): 1560-1570. http://smartsearch.nstl.gov.cn/paper_detail.html?id=05dc5bcf4691c9ac999865bbe0a71ac7
    [27]
    Wang B Y, Zhao L N, Xu H, et al. Probability distribution and partition of hourly rainfall during the rainy season over Sichuan Province. Torrential Rain and Disasters, 2018, 37(2): 115-123. doi:  10.3969/j.issn.1004-9045.2018.02.003
    [28]
    Li X F, Zhang Q H, Zou T J, et al. Climatology of hail frequency and size in China, 1980-2015. Journal of Applied Meteorology and Climatology, 2018, 57(4): 875-887. doi:  10.1175/JAMC-D-17-0208.1
    [29]
    Wang H, Li Y, Song L L, et al. Comparison of characteristics and environmental factors of thunderstorm gales over the Sichuan-Tibet Region. Journal of Applied Meteorological Science, 2020, 31(4): 435-446. doi:  10.11898/1001-7313.20200406
    [30]
    Atkins N T, Wakimoto R M. Wet microburst activity over the southeastern United States: Implications for forecasting. Weather and Forecasting, 1991, 6(4): 470-482. doi:  10.1175/1520-0434(1991)006<0470:WMAOTS>2.0.CO;2
    [31]
    Rickenbach T M, Rutledge S A. Convection in TOGA COARE: Horizontal scale, morphology, and rainfall production. Journal of Atmospheric Sciences, 1998, 55(17): 2715-2729. doi:  10.1175/1520-0469(1998)055<2715:CITCHS>2.0.CO;2
    [32]
    Moller A R, Doswell Ⅲ C A, Foster M P, et al. The operational recognition of supercell thunderstorm environments and storm structures. Weather and Forecasting, 1994, 9(3): 327-347. doi:  10.1175/1520-0434(1994)009<0327:TOROST>2.0.CO;2
    [33]
    Bluestein H B, Parks C R. A synoptic and photographic climatology of low-precipitation severe thunderstorms in the southern plains. Monthly Weather Review, 1983, 111(10): 2034-2046. doi:  10.1175/1520-0493(1983)111<2034:ASAPCO>2.0.CO;2
    [34]
    Rasmussen E N, Straka J M. Variations in supercell morphology. Part Ⅰ: Observations of the role of upper-level storm-relative flow. Monthly Weather Review, 1998, 126(9): 2406-2421. doi:  10.1175/1520-0493(1998)126<2406:VISMPI>2.0.CO;2
    [35]
    Roberts R D, Wilson J W. A proposed microburst nowcasting procedure using single-Doppler radar. Journal of Applied Meteorology and Climatology, 1989, 28(4): 285-303. doi:  10.1175/1520-0450(1989)028<0285:APMNPU>2.0.CO;2
    [36]
    Doswell C A, Burgess D W. Tornadoes and Tornadic Storms: A Review of Conceptual Models. The Tornado: Its Structure, Dynamics, Prediction, and Hazards. Geophysical Monograph, American Geophysical Union, 1993: 161-172. doi:  10.1029/GM079
    [37]
    Funk T W, Darmofal K E, Kirkpatrick J D, et al. Storm reflectivity and mesocyclone evolution associated with the 15 April 1994 squall line over Kentucky and Southern Indiana. Weather and Forecasting, 1999, 14(6): 976-993. doi:  10.1175/1520-0434(1999)014<0976:SRAMEA>2.0.CO;2
    [38]
    Markowski P M, Richardson Y P. Mesoscale Meteorology in Midlatitudes. Chichester: Wiley-Blackwell, 2010: 245-260.
    • Relative Articles
    • Supplements(0)
    • Cited By
  • 加载中
  • -->

Catalog

    Figures(9)

    Get Citation
    PDF
    XML
    Article views (1662) PDF downloads(172) Cited by()
    • Received : 2021-05-21
    • Accepted : 2021-07-09
    • Published : 2021-09-30
    Journal Online
    Contact

    © 2020 Journal of Applied Meteorological Science   京ICP备15006967号-1

    Supported by Beijing Renhe Information Technology Co. Ltd

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return