Weather warnings and watches cover much of the west coast of New Zealand as MetService warns the tropical moisture which has brought heavy rain will leave Aotearoa "with a bang".
But before it moves on, MetService warns an "intense period of rain and thunderstorms" will move across the motu on Tuesday - lashing already soaked western and northern regions of the North and South Islands.
In a statement, MetService meteorologist Jessie Owen said the band of rain currently lying over the West Coast of the South Island is expected to really come to life on Monday.
"When it moves back across the country tomorrow it will bring a burst of very heavy rain to those same areas that have been affected over the last week."
MetService's weather watches and warnings
Northland has been issued a heavy rain warning from 7am Tuesday to 7pm Tuesday. The region is also under a severe thunderstorm watch from 10am Tuesday to 5pm Tuesday.
Auckland including Great Barrier Island and Coromandel Penisula is also under a heavy rain warning from 12pm Tuesday to 12am Tuesday.
Metservice has also issued a thunderstorm warning for Auckland, Great Barrier Island, Coromandel Peninsula and Northland from Tuesday afternoon.
"An active front is expected to bring thunderstorms Tuesday afternoon and evening. Some of these thunderstorms may become severe, producing localised torrential rain in excess of 40 mm/h and a slight chance of a damaging tornado," Metservice says on its website.
"Expect thunderstorm activity to ease in Auckland Tuesday early evening and Coromandel Peninsula Tuesday night.
"Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.
"Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain. If any tornadoes occur, they will only affect very localised areas."
North Taranaki's heavy rain watch comes into effect from 9am Tuesday and ends 8pm Tuesday.
Mount Taranaki's heavy rain warning comes into effect at 9am Tuesday until 9pm Tuesday.
Bay of Plenty is under heavy rain watch from 4pm Tuesday to 6am Wednesday.
Tasman from Motueka westwards will be under a heavy rain warning from 6am Tuesday to 11pm Tuesday, with rainfall amounts expected to exceed MetService's criteria there as well.
Marlborough about and north of the Awatere Valley, Nelson, Tasman south and east of Motueka's heavy rain watch begins at 8am Tuesday and will last until 1am Wednesday.
"Rainfall amounts may exceed warning criteria and this watch is likely to be upgraded to a warning closer to the time," MetService's website said.
Buller's heavy rain watch comes into effect at 4am Tuesday and ends 9pm Tuesday.
Headwaters of Canterbury Lake, River about and south of Arthur's Pass are under a heavy rain warning from 8pm Monday to 8pm Tuesday.
Headwaters of Otago Lakes and Rivers' heavy rain watch comes into effect from 3pm Monday and ends 1pm Tuesday.
Fiordland north of Doubtful Sound will be under a heavy rain warning from 1pm Monday to 1pm Tuesday.
"People are urged to stay up to date with the watches and warnings. Warnings which are updated routinely every day mid-morning and in the evening."
MetService said the rain band will move quicker than it did last week but will whip regions with "very intense rainfall" and there is the potential for "localised torrential rainfall rates with thunderstorms".
"This very heavy rain will be falling on already saturated ground, so impacts such as surface flooding, rising rivers, and slips are likely."
But as the tropical air leaves, a low-pressure system from the Tasman Sea and a cold front southwest of Aotearoa will hit on Wednesday.
"This drops temperature significantly as far north as Kaitaia, and brings further rain and strong winds, as well as son to low levels."
MetService said snow is expected to lower to about 400 metres over the South Island on Wednesday, and about 800 meters over the central North Island on Thursday.
"This colder air is expected to spread right up the country, bringing a distinctly wintery feel. Wellingtonians should only expect a maximum of 10C on Thursday, 5C lower than the expected low of 15C overnight Monday," Owen said.
