A heavy rain and strong wind warnings have been issued for Northland with gusts of up to 120km/h and thunder storms forecast.
In the latest forecast MetService says a strong northeasterly flow is expected to bring a very warm and moist airmass onto New Zealand today and tomorrow.
The heaviest rain on Wednesday and Thursday is likely to affect Northland, where in the 18 hours from 3pm today to 9am tomorrow it's expected 100 to 150mm to accumulate, with peak intensities between 20 to 30mm per hour with thunderstorms possible tonight.
The rain could cause rivers and streams to rise rapidly, slips and localised flooding.
The strongest winds are expected to affect the north and west of the North Island where northeasterlies may become severe, gusting 120km/h or more from this afternoon or evening.
Winds of this strength have the potential to damage trees, powerlines and unsecured structures. Driving conditions may also be hazardous, especially for high sided vehicles and motorcycles.