Pattern change in the U.S. especially featuring major precipitation events often is caused by presence of the Madden Julian oscillation or a tropical cyclone.

Modern-day El Nino episodes have a tendency to occur while many other parts of the global oceans are also warmer than normal. This observation is a large change from the previous strong El Nino episodes of 1982-83/1997-98 when most of the oceanic heat and influence on atmospheric climate was consolidated in the tropical East Pacific. Consequently, our understanding of El Nino climate rooted in the influence on the atmosphere by the 1982-83/1997-98 warm ENSO events is different for many regions.

An intense high level atmospheric polar vortex developed during late winter. Strong positive arctic oscillation identifies the presence of the strong polar vortex. The polar vortex pattern caused extreme temperature the past 30 days in the U.S. BUT ALSO the excessive precipitation leading to early spring flooding.

If ENSO continues cooling into mid-year what would be the (ENSO) influence on Great Plains and South America precipitation pattern for February through May?