• Adams, D. K., and Comrie A. C. , 1997: The North American monsoon. Bull. Amer. Meteor. Soc., 78 , 21972213.

  • Anderson, B. T., Roads J. O. , and Chen S. C. , 2000a: Large-scale forcing of summertime monsoon surges over the Gulf of California and the southwestern United States. J. Geophys. Res., 105 (D19) 2445524467.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Anderson, B. T., Roads J. O. , Chen S. C. , and Juang H-M. H. , 2000b: Regional simulation of the low-level monsoon winds over the Gulf of California and southwestern United States. J. Geophys. Res., 105 (D14) 1795517969.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Anthes, R. A., 1982: Tropical Cyclones. Amer. Meteor. Soc., 208 pp.

  • Brenner, I. S., 1974: A surge of maritime tropical air—Gulf of California to the southwestern United States. Mon. Wea. Rev., 102 , 375389.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Djuric, D., 1994: Weather Analysis. Prentice Hall, 304 pp.

  • Douglas, M. W., 1995: The summertime low-level jet over the Gulf of California. Mon. Wea. Rev., 123 , 23342347.

  • Douglas, M. W., and Li S. , 1996: Diurnal variation of the lower-tropospheric flow over the Arizona low desert from SWAMP-1993 observations. Mon. Wea. Rev., 124 , 12111224.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Douglas, M. W., Maddox R. A. , Howard K. , and Reyes S. , 1993: The Mexican monsoon. J. Climate, 6 , 16651677.

  • Hales J. E. Jr., , 1972: Surges of maritime tropical air northward over the Gulf of California. Mon. Wea. Rev., 100 , 298306.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fuller, R. D., and Stensrud D. J. , 2000: The relationship between easterly waves and surges over the Gulf of California during the North American monsoon. Mon. Wea. Rev., 128 , 29832989.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Instituto Mexicano de Tecnología del Agua, 1999: ERIC: Extractor Rápido de Informacion Climatológica. CD-ROM. [Available from Instituto Mexicano de Tecnología del Agua, Paseo Cuauhnáhuac 8532, Juitepec, Morelos, México.].

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors. 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Meitin, J. G., Howard K. W. , and Maddox R. A. , 1991: Southwest area monsoon project. Daily operations summary. [Available from National Severe Storms Laboratory, Norman, OK 73069.].

    • Search Google Scholar
    • Export Citation
  • Press, W. H., Flannery B. P. , Teukolsky S. A. , and Vetterling W. T. , 1986: Numerical Recipes: The Art of Scientific Computing. Cambridge University Press, 818 pp.

    • Search Google Scholar
    • Export Citation
  • Reed, R. J., Norquist D. C. , and Recker E. E. , 1977: The structure and properties of African wave disturbances as observed during phase III of GATE. Mon. Wea. Rev., 105 , 317333.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Reyes, S., Douglas M. W. , and Maddox R. A. , 1994: El monzón del suroeste de Norteamérica (TRAVASON/SWAMP). Atmósfera, 7 , 117137.

  • Stensrud, D. J., Gall R. L. , and Nordquist M. K. , 1997: Surges over the Gulf of California during the Mexican monsoon. Mon. Wea. Rev., 125 , 417437.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 6 6 6
PDF Downloads 9 9 9

Summertime Surges over the Gulf of California: Aspects of Their Climatology, Mean Structure, and Evolution from Radiosonde, NCEP Reanalysis, and Rainfall Data

View More View Less
  • 1 National Severe Storms Laboratory, Norman, Oklahoma
  • | 2 Cooperative Institute for Mesoscale Meteorological Studies, The University of Oklahoma, Norman, Oklahoma
Restricted access

Abstract

This paper describes aspects of summertime northward surges of low-level moisture over the Gulf of California, based on 9 yr (1980–88) of radiosonde observations and also from NCEP reanalyses. These events are usually referred to as “gulf surges” by forecasters in the southwestern United States. A composite structure of 38 well-marked surge passages at Empalme, Mexico, during this period is presented. Radiosonde observations were composited to obtain the synoptic-scale structure of the surge from 2 days before to 2 days after the surge passage at Empalme. The composites reveal that the surges, strongest in the lower troposphere, are associated with low-latitude cyclonic perturbations that pass south of the Gulf of California. The composite cyclonic perturbation associated with the surges can be traced back to the western Gulf of Mexico 2 days prior to surge passage at Empalme. Composites based on the NCEP reanalyses for the same dates also show a similar evolution, though with somewhat weaker amplitude. Rainfall data from Mexican stations along the eastern side of the Gulf of California show that the surges modulate the climatological daily rainfall totals by ∼15%–30%. The evolution of surges is shown to be related to the propagation of tropical storms over the eastern Pacific Ocean.

Corresponding author address: Michael W. Douglas, National Severe Storms Laboratory, 1313 Halley Circle, Norman, OK 73069. Email: Michael.Douglas@nssl.noaa.gov

Abstract

This paper describes aspects of summertime northward surges of low-level moisture over the Gulf of California, based on 9 yr (1980–88) of radiosonde observations and also from NCEP reanalyses. These events are usually referred to as “gulf surges” by forecasters in the southwestern United States. A composite structure of 38 well-marked surge passages at Empalme, Mexico, during this period is presented. Radiosonde observations were composited to obtain the synoptic-scale structure of the surge from 2 days before to 2 days after the surge passage at Empalme. The composites reveal that the surges, strongest in the lower troposphere, are associated with low-latitude cyclonic perturbations that pass south of the Gulf of California. The composite cyclonic perturbation associated with the surges can be traced back to the western Gulf of Mexico 2 days prior to surge passage at Empalme. Composites based on the NCEP reanalyses for the same dates also show a similar evolution, though with somewhat weaker amplitude. Rainfall data from Mexican stations along the eastern side of the Gulf of California show that the surges modulate the climatological daily rainfall totals by ∼15%–30%. The evolution of surges is shown to be related to the propagation of tropical storms over the eastern Pacific Ocean.

Corresponding author address: Michael W. Douglas, National Severe Storms Laboratory, 1313 Halley Circle, Norman, OK 73069. Email: Michael.Douglas@nssl.noaa.gov

Save