El Niño, the climate cycle in the tropical Pacific Ocean that can reconfigure weather patterns, is slowly but steadily building for 2019 — but there is a component of it that is still missing in action.
Why it matters: El Niño events are one of the most consequential forces that can tip the odds in favor of particular weather patterns. But they require both unusually warm ocean temperatures in the tropical Pacific and changes in the atmosphere — and so far, the atmosphere hasn't changed.