High pressure battles rain for control of the country, with warnings that wet weather is 'critical' to drought conditions.
Next week low pressure fueled by La Nina will tumble down from the tropics towards New Zealand, but its progress will be halted by expanding high pressure.
"Rain that is trying to penetrate into dry northern New Zealand will be torn apart by more powerful high pressure further south," WeatherWatch says.
"Parts of New Zealand are now well into their second year of rainfall deficit and increased high pressure is to blame."
So far most of the very heavy tropical rain looks like it will fall north of New Zealand. However, WeatherWatch says the Far North, Northland and Hawke's Bay look to have the better chances of rain next week.
"The low next week shows a chance of bringing in some soaking rains but isn't locked in due to the dominating high-pressure belt," says head forecaster Philip Duncan.
"The rain next week is critical and if it fails to arrive then this will shift things up a gear as far as drought conversations go".
MetService says it is tracking the low and there's still uncertainty over its path and intensity.
"During Monday and Tuesday, there is moderate confidence of warning amounts of rain falling in eastern parts of Northland, northeastern parts of Auckland including Great Barrier Island, and Coromandel Peninsula. There is low confidence of heavy rain about the ranges of Gisborne during Tuesday," it says.
"A ridge of high pressure builds over the South Island on Tuesday, then spreads north onto the North Island on Wednesday and pushes the low-pressure system away from the North Island. On Thursday, the ridge should cover the whole country."