ENSO Related Seasonal Range Prediction over South America

Seasonal range prediction over North America has been based on intraseasonal variability related to the Pacific North America (PNA) pattern as well as the interannual variability related to El Nino and Southern Oscillation (ENSO). These teleconnective phenomena have an impact on atmospheric blocking which also have an impact on long-term conditions for North America. Similar relationships may be of use for seasonal range prediction over South America as well. Previous studies have examined ENSO-related variability on the South Pacific Jetstream as well as that of atmospheric blocking. Using the National Centers for Environmental Prediction / National Center for Atmospheric Research (NCEP / NCAR) reanalyses, the character of the winter and summer season circulations were studied over the South Pacific / South America sector from 2000 – 2016. Initial results show that there is a negative correlation in the upper air circulation over the East Pacific and South America from winter to summer. Also, the interannual variability in the jet-stream pattern for the region as related to ENSO shows a 180 degrees phase difference. Finally, there is evidence that the circulation pattern for the 2000 – 2016 may be different from that of the latter part of the 20^th century as indicated by a recent reversal of the internannual variability of atmospheric blocking over the South Pacific Region.