Download the Climate Impact Company ENSO Forecast
It’s been a wild ride for both the ENSO regime and forecasts of that pattern since the ending of the 2015-16 El Nino collapse. Historically, the eastward piling warm water in the tropical East Pacific causing El Nino sloshes back into the West Pacific causing El Nino’s demise and initiates an equally strong La Nina is equatorial temperatures cool and sea level lowers.
But not in 2016. The record warmth of the global oceans prevented the “slosh” from occurring and the East Pacific tropics managed only marginally cool last year. For the most part, this ENSO regime was not forecast by models.
In 2017 El Nino tried to return – also not forecast by models. During quarter 1 of 2017 super warm water off the northwest coast of South America gathered and caused the local climate of northwest South America to spill buckets of rain causing widespread flooding from Columbia to Peru. Of course this ocean warming would spread west and cause a widespread El Nino. At least that’s the historical understanding of how ENSO works.
But that didn’t happen. The convection pattern in northwest South America was so intense that all the heat in the upper oceans was dissipated by that event. Madden Julian oscillation finally arrived with intensity later this past spring to ease trade winds and allow the warmer than normal ocean to spread westward both at the surface and the subsurface but the warming is limited. The Nino34 SSTA has been at the El Nino threshold since April 17 so an actual weak El Nino could develop in 4 weeks if the marginal warmth appears.
That’s a NOAA call…El Nino onset or not. How they handle this situation is anyone’s guess but at the moment they have no eL Nino watch in-place (although Bureau of Meteorology/Australia does).
So what will happen? In my view this is the ultimate ignore the models forecast. What I see is a near record warm global ocean surface, warming off the west coast of South America and a resurgent warm phase of the Pacific decadal oscillation. These factors tell me that a run at El Nino is going to return after northern hemisphere summer. The energy/fuel to initiate El Nino I the short-term is not sufficient.
Bottom line? Neutral ENSO to AUG/SEP then El Nino could return later this year.
