A band of rain is slowly creeping closer to the upper North Island Friday afternoon as the sub-tropics once again start to move southwards, but WeatherWatch.co.nz says a newly forming low further north is one to keep a closer eye on.

The publicly owned rain radar network shows rain moving in from the north east, and although light it is bringing some rain to areas on the east coast from Whangarei to Coromandel Peninsula and near Waiheke Island, in the Hauraki Gulf.

However it’s the incoming low on Sunday and Monday that is likely to bring a drenching to some areas.

WeatherWatch.co.nz has upgraded their Auckland forecast to include “heavy rain” on Sunday as this developing low moves south east towards Bay of Plenty and East Cape.

The weather news authority says it’s been monitoring the models closely and believes that this new low will likely bring wetter conditions than that of ex-tropical cyclone Zelia for residents in the upper North Island.

Zelia tracked a little too far west of the upper North Island to deliver much needed rain earlier this week in places like Waikato, Northland and Bay of Plenty.

It appears Sunday and Monday will see heavy rain falling across northern and north eastern parts of the North Island, including Northland, Auckland, Coromandel Peninsula, Bay of Plenty, East Cape and Gisborne.  Waikato is expected to again be on the borderline of the heaviest rain but WeatherWatch.co.nz is confident some parts will get healthy rainfall totals.

Head weather analyst Philip Duncan says conditions look more promising for substantial rain this weekend than they did before Zelia moved in.  “We think this new low will bring in more rain than the system earlier this week because this one is just starting to develop into a new low pressure system – it’s healthy and placed well.  Zelia was old, tired and falling apart by the time she reached us”.

However Mr Duncan says unlike Zelia this system won’t bring heavy rain to the West Coast of the South Island – where a sunny weekend is forecast.  Clouds and drizzle may affect the east coast of the South Island however with a much cooler easterly wind.

The MetService says they have “high confidence” of heavy rain falling across a number of North Island regions and people are advised to keep up to date with the latest forecasts and warnings.

WeatherWatch.co.nz will closely monitor this incoming low and will provide extra updates across the weekend.