A swathe of severe weather warnings are in force as a tropically-fuelled rainmaker is set to bring a short, sharp deluge to central New Zealand this holiday weekend.

The incoming storm, set to sweep across the country over the next 24 hours, will see the worst affected regions get up to a month’s worth of rain in just 20 hours.

It comes as holidaymakers leave for an extended long weekend break with NZTA warning of high traffic volumes on central North Island roads.

Heavy rain alerts have been issued across central New Zealand from Westland to Taranaki.

There are also strong wind watches in force with gales expected for Taranaki and Whanganui and the deep south.

MetService warned there could be major impacts for Wellington with the incoming storm expected to bring a level of disruption.

This morning the capital was under a heavy rain watch, with periods of heavy rain due to start from 4pm and lasting across the night.

“Even if warning criteria is not reached, there is still a risk of impacts like surface flooding, slips, and rising rivers in already sodden areas.

“These hazards, along with poor visibility in heavy rain, can also cause travel delays and disruptions,” said MetService.

An orange heavy rain warning has been issued for Horowhenua, Kāpiti Coast, the Tararua Range, Mt Taranaki., Tasman northwest of Motueka and Westland.

MetService said periods of heavy rain would start falling from 4pm today at the bottom of the North Island, with the Tararua Range expected to record more than 150mm of rain over the following 20 hours.

It warned the heavy rain may cause streams and rivers to rise rapidly.

The intense deluge also brought a threat of surface flooding and slips with driving conditions possibly proving hazardous.

A strong wind watch was in force from 7pm today for Taranaki, Taihape and north of Whanganui. Northerly winds were expected to batter the regions overight from 7pm.

Niwa said with the heavy rain falling on the upper South Island and lower North Island from late Friday through to Saturday morning there was a possiblity of rapidly rising rivers and localised flooding.

It said the northern South Island was likely see the heaviest deluges, with as much as a month’s worth of rain falling.

The stormy weather was expected to move away to the east of the country on Saturday.