Apparently the wind belts around the equator flip about once every two years. This past year, NASA found that the flip occurred much earlier than it expected. Watch the short video at this url to learn more about this phenomena and how it might be related to the 2015-16 El Nino event.
http://www.businessinsider.com/nasa-explain-unexpected-atmosphere-flip-wind-direction-2016-9?utm_source=feedburner&utm_medium=referral
