ENSO comes in different flavors and types, which we addressed in an earlier blog post:

http://www.climate.gov/news-features/blogs/enso/enso-flavor-month

We find that the strongest El Nino events have above-average SSTs near Ecuador.  However, weaker El Nino events often do not extend all the way to South America.  The current case is weak and, as a result, we're not surprised to see it associated with characteristics that are more "Central Pacfiic."  

One way to quickly compare different types is to compare the relative values of the Nino regions.  Often the Nino-4 index is > Nino-3 index for weaker Central Pacific El Ninos and Nino-3 is > Nino-4 for stronger Eastern Pacific El Ninos.  Data