Summer Precipitation Anomalies
During Building El Niņo Events
There has been much speculation about whether the heavy and prolonged "monsoonal flow" precipitation early this summer into Southwest and the southern Plains has been a characteristic of the building El Niņo. Below are the precipitation anomalies for the years where the Oceanic Niņo Index was at least +0.5 for the May-Jun-Jul (MJJ) period and it was increasing, along with a composite map of all the years.  Based on the composite there does not appear to me an overriding "signal".
1957 1963 1965
1972 1982 1991
1986 1997 2002

produced by Jan Null, CCM
Golden Gate Weather Services