Other than the model forecasts, there isn’t a whole lot of evidence right now that suggests we can more confidently expect El Niño to develop later this year. As Aaron covered in his post last month, one of the factors we look at is the “warm water volume,” the amount of warmer water below the surface of the tropical Pacific. To vastly simplify his point (really, you should check out his great post), more warm water than average during the spring is sometimes, but not always, followed by El Niño. On the other hand, less warm water than average rarely precedes El Niño.