Observed splitting eastbound propagation of subsurface warm water over the equatorial Pacific in early 2014

El Niño, as characterized by above average sea surface temperatures in the equatorial tropical Pacific, is the largest source of natural climate variability from seasonal to interannual scales and can profoundly reshape the global weather patterns. Currently, the tropical Pacific Ocean appears to be primed for a potentially significant El Niño event, and some similarities exist between the oceanic and atmospheric states in early 2014 compared to the observations shortly before the onset of the 1997/1998 Super El Niño event. For example, as one of the most important early signs of El Niño, a splitting eastbound propagation of the subsurface warm water is evident over the equatorial Pacific since January 2014. In this study, the pulses of subsurface warm water are reflected by the Kelvin waves over the equatorial Pacific estimated from the satellite altimetry data. Results show that the current (i.e., March 2014) Kelvin wave over the equatorial Pacific has achieved the largest amplitude compared to those in the corresponding period prior to the El Niño events since the availability of satellite altimetry, and is even significantly larger than the one that preceded the 1997/1998 Super El Niño event. As the Kelvin waves can help induce El Niño conditions within about 2-4 months, the current fastest/strongest eastbound propagation of subsurface warm water indicates that the likelihood of an El Niño event will significantly increase during the next several months in 2014.