2021 North American Monsoon Recap

October 15, 2021

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2021 North American Monsoon marked by wetter-than-normal conditions in southwestern US

  • The North American Monsoon (NAM) refers to a shift in the synoptic-scale wind pattern that transports low-to-midlevel moisture from the Eastern Pacific and Gulf of Mexico into the southwestern US during summer
  • The NAM is an important source of annual precipitation for parts of the southwestern US
  • Unlike the stronger Indian Monsoon, the NAM is characterized by episodic bursts of moisture transport and rainfall
  • The 2021 monsoon season was characterized by an abundance of moisture and frequent precipitation episodes, particularly in Arizona
  • Arizona experienced its 9th wettest July–September period since 1895
  • Anomalously wet conditions during July–September brought much-needed drought relief to portions of the Four Corners Region










Summary provided by C. Castellano, J. Kalansky, and F. M. Ralph; 15 October 2021