Another large low is rolling in and this one will also be tapping into sub-tropical air, creating localised heavy downpours across northern New Zealand on Wednesday.

Most at risk is Northland, Auckland, Coromandel Peninsula and Bay of Plenty, with perhaps Bay of Plenty having the highest risk for torrential rain into the afternoon and evening.

Isolated thunderstorms are also possible as the warm sub-tropical northerlies mix with a late day/overnight southerly change.

The torrential downpours are hit and miss – use the rain maps we have to work out the highest risk areas in advance, then at the time use them along with the MetService rain radar to track the movements of these heaviest downpours.

Wednesday’s sub-tropical event is one of many so far this Autumn and Winter – with WeatherWatch.co.nz forecasting yet another low (a smaller one) coming in directly towards the upper North Island this Sunday, with hit and miss heavy downpours again and warmer than average air.

A cold change is coming!
If you’re wondering when the colder non-subtropical weather arrives then this might help – at this stage WeatherWatch.co.nz is forecasting a colder nationwide south to south west flow across the country from about July 5 to July 8, followed by a high. This could bring a return to frosts for some regions and some snow showers to ski fields in both islands.

Subtropics return mid-July
However, at the end of the high in July’s second week, it looks likely we’ll once again see a warm sub-tropical airflow return across some parts of the country with rain coming back to the north and west of both islands for a time.

– Rain map for 3pm Wednesday / Weathermap.co.nz

– WeatherWatch.co.nz