Impact of the Summer Monsoon Westerlies on the South China Sea Tropical Cyclone Genesis in May

Tsing-Chang Chen Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa

Search for other papers by Tsing-Chang Chen in
Current site
Google Scholar
PubMed
Close
,
Jenq-Dar Tsay Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa

Search for other papers by Jenq-Dar Tsay in
Current site
Google Scholar
PubMed
Close
,
Jun Matsumoto Department of Geography, Tokyo Metropolitan University, Tokyo, and Department of Coupled Ocean–Atmosphere–Land Processes Research, JAMSTEC, Yokosuka, Japan

Search for other papers by Jun Matsumoto in
Current site
Google Scholar
PubMed
Close
, and
Jordan Alpert National Centers for Environmental Predication/Environmental Modeling Center, College Park, Maryland

Search for other papers by Jordan Alpert in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

After the onset of the Southeast Asian summer monsoon in mid-May, the South China Sea (SCS) trough is deepened by the intensified monsoon westerlies to facilitate the development of a synoptic cyclonic shear flow. This shear flow forms an environment favorable for the SCS tropical storm (TS)/typhoon (TY) genesis triggered by the surge of this monsoon circulation. This genesis mechanism has not been well documented. Seventeen named SCS TS/TY geneses in May over 1979–2016 occurred under the following environmental conditions/processes: 1) with its maximum located south of 15°N, the intensified monsoon westerlies are extended eastward beyond 120°E, 2) the synoptic SCS cyclonic shear flow is developed by the tropical easterlies fed by a northeast Asian cold surge (or a North Pacific cold-air outbreak) and the intensified monsoon westerlies, and 3) SCS TS/TY genesis is triggered by the surge of monsoon flow. The accuracy of the monthly mean forecasts is limited. However, it is found that SCS TS/TY genesis only occurs after the existence of persistent, strong, monsoon westerlies lasting for at least 5 days. Forecasts from the National Centers for Environmental Prediction Global Forecast System (2004–16) and the Global Ensemble Forecast System (1985–2003) cover these 15 SCS TS/TY geneses. The requirements for SCS TS/TY genesis in May described above are met by the 5-day-mean Southeast Asian summer monsoon circulation. Based on a statistical analysis of 5-day forecasts for these TS/TY geneses, a four-step forecast advisory is introduced. The forecasts for SCS TS/TY genesis can be made 3 days prior to occurrence.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/WAF-D-16-0189.s1.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author e-mail: Tsing-Chang (Mike) Chen, tmchen@iastate.edu

Abstract

After the onset of the Southeast Asian summer monsoon in mid-May, the South China Sea (SCS) trough is deepened by the intensified monsoon westerlies to facilitate the development of a synoptic cyclonic shear flow. This shear flow forms an environment favorable for the SCS tropical storm (TS)/typhoon (TY) genesis triggered by the surge of this monsoon circulation. This genesis mechanism has not been well documented. Seventeen named SCS TS/TY geneses in May over 1979–2016 occurred under the following environmental conditions/processes: 1) with its maximum located south of 15°N, the intensified monsoon westerlies are extended eastward beyond 120°E, 2) the synoptic SCS cyclonic shear flow is developed by the tropical easterlies fed by a northeast Asian cold surge (or a North Pacific cold-air outbreak) and the intensified monsoon westerlies, and 3) SCS TS/TY genesis is triggered by the surge of monsoon flow. The accuracy of the monthly mean forecasts is limited. However, it is found that SCS TS/TY genesis only occurs after the existence of persistent, strong, monsoon westerlies lasting for at least 5 days. Forecasts from the National Centers for Environmental Prediction Global Forecast System (2004–16) and the Global Ensemble Forecast System (1985–2003) cover these 15 SCS TS/TY geneses. The requirements for SCS TS/TY genesis in May described above are met by the 5-day-mean Southeast Asian summer monsoon circulation. Based on a statistical analysis of 5-day forecasts for these TS/TY geneses, a four-step forecast advisory is introduced. The forecasts for SCS TS/TY genesis can be made 3 days prior to occurrence.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/WAF-D-16-0189.s1.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author e-mail: Tsing-Chang (Mike) Chen, tmchen@iastate.edu

Supplementary Materials

    • Supplemental Materials (PDF 41.23 MB)
Save
  • Ananthakrishnan, R., and M. K. Soman, 1988: The onset of the southwest monsoon over Kerala: 1901–1980. J. Climatol., 8, 283296, doi:10.1002/joc.3370080305.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, G., 2011: How does shifting Pacific Ocean warming modulate on tropical cyclone frequency over the South China Sea? J. Climate, 24, 46954700, doi:10.1175/2011JCLI4140.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, T.-C., and J.-M. Chen, 1995: An observation study of the South China Sea monsoon during the 1979 summer: Onset and life cycle. Mon. Wea. Rev., 123, 22952318, doi:10.1175/1520-0493(1995)123<2295:AOSOTS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, T.-C., S.-Y. Wang, W.-R. Huang, and M.-C. Yen, 2004a: Variation of the East Asian summer monsoon rainfall. J. Climate, 17, 744762, doi:10.1175/1520-0442(2004)017<0744:VOTEAS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, T.-C., S.-Y. Wang, M.-C. Yen, and W. A. Gallus Jr., 2004b: Role of the monsoon gyre in the interannual variation of tropical cyclone formation over the western North Pacific. Wea. Forecasting, 19, 776785, doi:10.1175/1520-0434(2004)019<0776:ROTMGI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, T.-C., J.-D. Tsay, M.-C. Yen, and E. O. Cayanan, 2010: Formation of the Philippine twin tropical cyclones during the 2008 summer monsoon onset. Wea. Forecasting, 25, 13171341, doi:10.1175/2010WAF2222395.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, X., Y. Wang, and K. Zhao, 2015: Synoptic flow patterns and large-scale characteristics associated with rapidly intensifying tropical cyclones in the South China Sea. Mon. Wea. Rev., 143, 6487, doi:10.1175/MWR-D-13-00338.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cossuth, J. H., R. D. Knabb, D. P. Brown, and R. E. Hart, 2013: Tropical cyclone formation guidance using pregenesis Dvorak climatology. Part I: Operational forecasting and predictive potential. Wea. Forecasting, 28, 100118, doi:10.1175/WAF-D-12-00073.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553597, doi:10.1002/qj.828.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Goh, A. Z.-C., and J. C.-L. Chan, 2009: Interannual and interdecadal variations of tropical cyclone activity in the South China Sea. Int. J. Climatol., 30, 827843, doi:10.1002/joc.1943.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gray, W. M., 1998: The formation of tropical cyclones. Meteor. Atmos. Phys., 67, 3769, doi:10.1007/BF01277501.

  • Halperin, D. J., R. E. Hart, H. E. Fuelberg, and J. H. Cossuth, 2017: The development and evaluation of a statistical–dynamical tropical cyclone genesis guidance tool. Wea. Forecasting, 32, 2746, doi:10.1175/WAF-D-16-0072.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hamill, T. M., G. T. Bates, J. S. Whitaker, D. R. Murray, M. Fiorino, T. J. Galarneau, Y. Zhu, and W. Lapenta, 2013: NOAA’s second-generation global medium range ensemble forecast dataset. Bull. Amer. Meteor. Soc., 94, 15531565, doi:10.1175/BAMS-D-12-00014.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hamill, T. M., J. S. Whitaker, D. R. Murray, M. Fiorino, and T. J. Galarneau, 2016: A description of the 2nd-generation NOAA global ensemble reforecast data set. NOAA/ESRL, 10 pp. [Available online at http://www.esrl.noaa.gov/psd/forecasts/reforecast2/README.GEFS_Reforecast2.pdf.]

  • JTWC, 2016: JTWC Tropical Cyclone Best Track Data Site. Joint Typhoon Warning Center. [Available online at http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/best_tracks/.]

  • Kajikawa, Y., and B. Wang, 2012: Interdecadal change of the South China Sea summer monsoon onset. J. Climate, 25, 32073218, doi:10.1175/JCLI-D-11-00207.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lau, K.-M., and S. Yang, 1997: Climatology and interannual variability of the Southeast Asian summer monsoon. Adv. Atmos. Sci., 14, 141162, doi:10.1007/s00376-997-0016-y.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liu, B., C. Zhu, Y. Yuan, and K. Xu, 2016: Two types of interannual variability of South China Sea monsoon onset related to the SST anomalies before and after 1993/94. J. Climate, 29, 69576958, doi:10.1175/JCLI-D-16-0065.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Matsumoto, J., 1997: Seasonal transition of summer rainy season over Indochina and adjacent monsoon region. Adv. Atmos. Sci., 14, 231245, doi:10.1007/s00376-997-0022-0.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Moron, V., A. Lucero, F. Hilario, B. Lyon, A. W. Robertson, and D. DeWitt, 2009: Spatio-temporal variability and predictability of summer monsoon onset over the Philippines. Climate Dyn., 25, 11591177, doi:10.1007/s00382-008-0520-5.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • NCEP, 2003: The GFS Atmospheric Model. NCEP Office Note 442, 14 pp. [Available online at http://nws.noaa.gov/ost/climate/STIP/AGFS_DOC_1103.pdf.]

  • Neumann, C. J., 1993: Global guide to tropical cyclone forecasting. Global Guide to Tropical Cyclone Forecasting: 1983, WMO/TC 560, Rep. TCP-31. [Available online at http://www.wmo.int/cycloneguide/.]

  • NWS/EMC, 2016: The Global Forecast System (GFS)—Global Spectral Model (GSM) (GSM version 13.0.2). NWS/Environmental Modeling Center. [Available online at http://www.emc.ncep.noaa.gov/GFS/doc.php.]

  • Ott, R. L., and M. T. Longnecker, 2001: An Introduction to Statistics Methods and Data Analysis. 5th ed. Duxbury Press, 1152 pp.

  • Ramage, C. S., 1952: Relationship of general circulation to normal weather over southern Asia and the western Pacific during the cool season. J. Meteor., 9, 403408, doi:10.1175/1520-0469(1952)009<0403:ROGCTN>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ramage, C. S., 1971: Monsoon Meteorology. International Geophysics Series, Vol. 15, Academic Press, 296 pp.

  • Ritchie, E. A., and G. J. Holland, 1999: Large-scale patterns associated with tropical cyclogenesis in the western Pacific. Mon. Wea. Rev., 127, 20272043, doi:10.1175/1520-0493(1999)127<2027:LSPAWT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • RSMC, 2016: RSMC best-track data. Regional Specialized Meteorological Center—Tokyo. [Available online at http://www.jma.go.jp/jma/jma-eng/jma-center/rsmc-hp-pub-eg/besttrack.html.]

  • Schumacher, A. B., M. DeMaria, and J. A. Knaff, 2009: Objective estimation of the 24-h probability of tropical cyclone formation. Wea. Forecasting, 24, 456471, doi:10.1175/2008WAF2007109.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, L., K.-H. Lau, and C.-H. Fung, 2007: The relative vorticity of ocean surface winds from the QuikSCAT satellite and its effects on the geneses of tropical cyclones in the South China Sea. Tellus, 59A, 562569, doi:10.1111/j.1600-0870.2007.00249.x.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, L., Z. Wen, R. Huang, and R. Wu, 2012: Possible linkage between the monsoon trough variability and the tropical cyclone activity over the western North Pacific. Mon. Wea. Rev., 140, 140150, doi:10.1175/MWR-D-11-00078.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, L., and Coauthors, 2014: Simulations of the present and late-twenty-first-century western North Pacific tropical cyclone activity using a regional model. J. Climate, 27, 34053424, doi:10.1175/JCLI-D-12-00830.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, L., Z. Wen, and R. Wu, 2015a: Influence of the monsoon trough on westward-propagating tropical waves over the western North Pacific. Part I: Observations. J. Climate, 28, 71087127, doi:10.1175/JCLI-D-14-00806.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, L., Z. Wen, and R. Wu, 2015b: Influence of the monsoon trough on westward-propagating tropical waves over the western North Pacific. Part II: Energetics and numerical experiments. J. Climate, 28, 93329349, doi:10.1175/JCLI-D-14-00807.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhou, W., and J. C.-L. Chan, 2007: ENSO and the South China Sea summer monsoon onset. Int. J. Climatol., 27, 157167, doi:10.1002/joc.1380.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 513 115 8
PDF Downloads 387 59 3