The equatorial Pacific's upper ocean temperatures are cooling dramatically as we head towards summer. This is being caused by tropical easterlies churning up cooler, deeper sea water to the ocean’s surface. The result is a classic ocean and atmospheric La Niña weather pattern signature.
With this weather pattern, it's likely there will be intense periods of rain bearing north-easterlies for the upper North Island during the next 6 months. It's also can bring an above average South Pacific cyclone season.