Sea surface temperatures are up. So why haven't forecasters declared El Niño conditions?
Chances that an El Niño will occur by summer are above 70%, hitting 80% by the fall. But subsurface temperature anomalies have tapered off some from earlier this spring, decreasing the odds the event will be as strong as the El Niño of 1997-98.
The forecast models are largely in agreement that SSTs will continue to trend upward, with the majority of models indicating a Niño3.4 index value above 0.5°C by early summer. Forecast show the chance of El Niño increasing during the remainder of the year, exceeding 65% during the summer.