Forecasters are warning more rain is making a beeline for already drenched areas of the country, bringing strong winds, heavy rain and thunderstorms.

After last week’s deluge, rain on the already sodden soils could mean slips and floods for regions across the top of the country.

MetService is warning that significant amounts of rain could fall in Northland, northern Auckland, and the Coromandel Peninsula today and tomorrow, as well as for the Bay of Plenty and Tairawhiti to the north of Ruatoria tomorrow.

It has placed a heavy rain watch on Northland from 3pm today until 3am tomorrow.

Niwa said the weather is tropically charged and is set to hit Northland first this evening before becoming more widespread across the weekend. The forecasting agency predicted the weather could be “damaging”.

“Yet another low will be approaching from the north Tasman Sea with rain and strong wind ramping up over the upper North Island [this] afternoon and evening,” MetService meteorologist Luis Fernandes said.

Strong winds will accompany the low-pressure system and there is a moderate risk of severe northeast gales in some regions of Northland, where a watch is in effect, Auckland, Coromandel, Waikato and Waitomo today.

Between 50mm and 100mm of rain is possible for parts of the island by midnight Friday.

MetService said the bands of rain would be fast-moving, and it expects large waves along exposed coastlines.

“This low is moving quicker than the previous weather systems that brought heavy rain and flooding this year, most recently last week,” Fernandes said.

However, with already saturated ground, any further heavy rain could be problematic, and strong wind is an added complication.

At this stage, Fernandes said MetService is unclear how much damage the fast-moving weather system will do.

“We used multiple weather forecasting models, and this far into the future they show many different options for how this weather plays out on Thursday and Friday,” Fernandes said.

Yesterday, it was revealed this year’s rain stood out drastically among 30 years of rainfall data.

Auckland received 90 per cent of its average annual rainfall in just a few months, running at about three times the 30-year baseline.

Much of that had come in one-off extreme events - notably the one-in-200-year Anniversary Weekend deluge that dropped several hundred millimetres of rain on suburbs over 24 hours and contributed to the city’s wettest month in at least 170 year