El Niño May Delay Onset of the Monsoon
Monsoon season officially began June 15th. The word "monsoon" is derived from the Arabic word "mausim" which means season . During the summer months, winds shift from our predominant westerly direction to a southerly direction. This allows moisture from the Gulf of California and the Gulf of Mexico to stream into the region. This year El Niño (warmer than average tropical Pacific Ocean water) is still present and predicted to continue through summer. El Niño is loosely correlated to the onset of our monsoon as the westerly storm track continues to stay active, suppressing the monsoon circulation.
NOAA's Climate Prediction Center is forecasting a slight tilt towards drier than average conditions through August in southern and central Arizona with equal chances for northern Arizona.
El Nino may feed into a wetter monsoon pattern late in the season as tropical storm systems may be pulled further north come September. Check out the presentation released by the NWS Tucson.
*Monsoon Outlook 2019*— NWS Tucson (@NWSTucson) May 31, 2019
* Later than normal start
* Below normal precipitation most likely June through August.
* Better chances for normal rainfall later in the monsoon (highly dependent on tropical systems in September)
* Above normal temperatures are expected. #azwx pic.twitter.com/pROS9v7koX