Batten down the hatches New Zealand - a turbulent end to the week is on the cards.

Some areas may get over 100mm of rain, Weatherwatch says.

From today, a northerly wind is strengthening.

Afternoon thunderstorms are likely in inland regions in the southern part of the North Island today and tomorrow. They spread to the South Island tomorrow and Thursday as a low-level northerly wind strengthens.


Some storms may be severe, producing locally heavy rainfall exceeding 30mm in an hour - and 100mm over a few days - as well as gusty winds, and possibly hail, a Weatherwatch spokesman said.

Following the northerly wind, a rapidly developing low pressure is expected to approach the North Island southeastward from the northern Tasman sea.

Northland and Auckland will be exposed by strong winds over gale force at times with wind gusts on Thursday and Friday.

Heavy rain is expected in those areas on Thursday during the day and and the Bay of Plenty and Waikato on Thursday night, spilling over into Friday.

MetService said that in Auckland, Coromandel Peninsula, Waikato, Waitomo, Taumarunui, Taupo, North Taranaki, northwest Nelson and the Kaikoura Coast, there was "moderate confidence" of heavy rain on Friday and Saturday.

There was high confidence heavy rain would fall in Northland, Bay of Plenty and areas around Gisborne.

"In addition, on Friday and Saturday there is moderate confidence of severe gales across the northern half of the North Island from North Taranaki across to Taupo and northern Gisborne, while our confidence reduces to low for the remainder of the North Island during this time.

"There remains some uncertainty as to the exact track of this low, but this weather system has the potential to bring significant severe weather to northern and central New Zealand."