We are grateful to I. Held, I. Orlanski, and G. Kiladis for constructive discussions in the course of this study. We would also like to thank G. Vecchi, J. Lanzante, G. Kiladas, Q. Ding, Z. Wang, and B. Wang and the anonymous official reviewers for their insightful comments, which led to considerable improvements of earlier versions of this manuscript. XJ acknowledges the support of the AOS visiting scientist program at Princeton University.
Bordoni, S. and B. Stevens, 2006: Principal component analysis of the summertime winds over the Gulf of California: A gulf surge index. Mon. Wea. Rev., 134:3393–3412.
Bordoni, S., P. E. Ciesielski, R. H. Johnson, B. D. McNoldy, and B. Stevens, 2004: The low-level circulation of the North American Monsoon as revealed by QuikSCAT. Geophys. Res. Lett., 31.L10109, doi:10.1029/2004GL020009.
Carleton, A. M., D. A. Carpenter, and P. J. Weser, 1990: Mechanisms of interannual variability of the southwest United States summer rainfall maximum. J. Climate, 3:999–1015.
Enomoto, T., B. J. Hoskins, and Y. Matsuda, 2003: The formation mechanism of the Bonin high in August. Quart. J. Roy. Meteor. Soc., 129:157–178.
Fukutomi, Y. and T. Yasunari, 1999: 10–25 day intraseasonal variations of convection and circulation over East Asia and western North Pacific during early summer. J. Meteor. Soc. Japan, 77:753–769.
Fukutomi, Y. and T. Yasunari, 2002: Tropical–extratropical interaction associated with the 10–25 day oscillation over the western Pacific during the northern summer. J. Meteor. Soc. Japan, 80:311–331.
Fuller, R. D. and D. J. Stensrud, 2000: The relationship between tropical easterly waves and surges over the Gulf of California during the North American monsoon. Mon. Wea. Rev., 128:2983–2989.
Gyoswami, B. N. and J. Shukla, 1984: Quasi-periodic oscillations in a symmetric general circulation model. J. Atmos. Sci., 41:20–37.
Higgins, R. W., Y. Yao, and X. L. Wang, 1997: Influence of the North American monsoon system on the U.S. summer precipitation regime. J. Climate, 10:2600–2622.
Higgins, R. W., Y. Chen, and A. V. Douglas, 1999: Interannual variability of the North American warm season precipitation regime. J. Climate, 12:653–680.
Higgins, R. W., W. Shi, and C. Hain, 2004: Relationships between Gulf of California moisture surges and precipitation in the southwestern United States. J. Climate, 17:2983–2997.
Hoskins, B. J. and T. Ambrizzi, 1993: Rossby wave propagation on a realistic longitudinally varying flow. J. Atmos. Sci., 50:1661–1671.
Hsu, H-H., 2005: East Asian monsoon. Intraseasonal Variability in the Atmosphere–Ocean Climate System, K. M. Lau and D. E. Waliser, Eds., Springer-Verlag, 63–94.
Huffman, G. J., R. F. Adler, M. M. Morrissey, D. T. Bolvin, S. Curtis, R. Joyce, B. McGavock, and J. Susskind, 2001: Global precipitation at one-degree daily resolution from multisatellite observations. J. Hydrometeor., 2:36–50.
Kawamura, R., T. Murakami, and B. Wang, 1996: Tropical and midlatitude 45-day perturbations during the northern summer. J. Meteor. Soc. Japan, 74:867–890.
Kiladis, G. N. and E. A. Hall-McKim, 2004: Intraseasonal modulation of precipitation over the North American monsoon region. Proc. 15th Symp. on Global Change and Climate Variations, Seattle, WA, Amer. Meteor. Soc., 11.4. [Available online at http://ams.confex.com/ams/pdfpapers/72428.pdf.].
Lau, K-M. and P. H. Chan, 1986: Aspects of the 40–50 day oscillation during the northern summer as inferred from outgoing longwave radiation. Mon. Wea. Rev., 114:1354–1367.
Lau, K-M. and H. Weng, 2002: Recurrent teleconnection patterns linking summertime precipitation variability over East Asia and North America. J. Meteor. Soc. Japan, 80:1309–1324.
Lau, N-C. and M. J. Nath, 2006: ENSO modulation of the interannual and intraseasonal variability of the East Asian monsoon—A model study. J. Climate, 19:4508–4530.
Liebmann, B. and C. A. Smith, 1996: Description of a complete (interpolated) outgoing longwave radiation dataset. Bull. Amer. Meteor. Soc., 77:1275–1277.
Livezey, R. E. and W. Y. Chen, 1983: Statistical field significance and its determination by Monte Carlo techniques. Mon. Wea. Rev., 111:46–59.
Mo, K. C. and R. W. Higgins, 1998: Tropical convection and precipitation regimes in the western United States. J. Climate, 11:2404–2423.
Mo, K. C. and J. Nogues-Paegle, 2005: Pan-America. Intraseasonal Variability in the Atmosphere–Ocean Climate System, K. M. Lau and D. E. Waliser, Eds., Springer-Verlag, 95–124.
Mullen, S. L., J. T. Schmitz, and N. O. Rennó, 1998: Intraseasonal variability of the summer monsoon over southeast Arizona. Mon. Wea. Rev., 126:3016–3035.
Negri, A. J., R. F. Adler, E. J. Nelkin, and G. J. Huffman, 1994: Regional rainfall climatologies derived from Special Sensor Microwave Imager (SSM/I) data. Bull. Amer. Meteor. Soc., 75:1165–1182.
Okabe, I. T., 1995: The North American monsoon. Ph.D. dissertation, University of British Columbia, 146 pp.
Sikka, D. R. and S. Gadgil, 1980: On the maximum cloud zone and the ITCZ over Indian longitudes during southwest monsoon. Mon. Wea. Rev., 108:1840–1853.
Stensrud, D. J., R. L. Gall, and M. K. Nordquist, 1997: Surges over the Gulf of California during the Mexican monsoon. Mon. Wea. Rev., 125:417–437.
Takaya, K. and H. Nakamura, 2001: A formulation of a phase-independent wave-activity flux for stationary and migratory quasigeostrophic eddies on a zonally varying basic flow. J. Atmos. Sci., 58:608–627.
Tam, C-Y. and N-C. Lau, 2005: The impact of ENSO on atmospheric intraseasonal variability as inferred from observations and GCM simulations. J. Climate, 18:1902–1924.
Tang, M. and E. R. Reiter, 1984: Plateau monsoons of the Northern Hemisphere: A comparison between North America and Tibet. Mon. Wea. Rev., 112:617–637.
Tian, B., I. M. Held, N-C. Lau, and B. J. Soden, 2005: Diurnal cycle of summertime deep convection over North America: A satellite perspective. J. Geophys. Res., 110.D08108, doi:10.1029/2004JD005275.
Wang, B. and Q. Zhang, 2002: Pacific–East Asian teleconnection. Part II: How the Philippine Sea anomalous anticyclone is established during El Niño development. J. Climate, 15:3252–3265.
Wang, B., R. Wu, and K-M. Lau, 2001: Interannual variability of Asian summer monsoon: Contrasts between the Indian and western North Pacific–East Asian monsoons. J. Climate, 14:4073–4090.