While a severe thunderstorm warning has been lifted in the Auckland region, it is not the end of ex-Tropical Cyclone Tam, which has been wreaking havoc across the top of the North Island this week.
Hundreds of lightning strikes and heavy rain hit the area yesterday, leading to localised flooding and scores of emergency services callouts.
According to MetService, the system lies west of New Zealand and is expected to slowly move east across the upper South Island during Sunday and Monday, while gradually weakening.
The forecaster this morning issued another thunderstorm watch, saying a line of storms producing localised heavy rain is expected to develop over southern Northland and Auckland early afternoon, and move slowly eastwards across the region.
MetService meteorologist said Alex Holden said the former cyclone remained over the Tasman Sea this morning, level with Kahurangi National Park.
The centre of the storm had moved south, and was now sitting over the Tasman, casting rain over the western coast.
He says that will linger there for a little while, as it tries to squeeze through the gap between the North and South Islands, before a high pressure system eases the rain from Monday.
There are two severe weather warnings in place, for Tasman and Taranaki Maunga.
There is also a heavy rain watch in place for ranges of Westland District through to 3pm Sunday.
Watches have also been issued for Gisborne north of Tokomaru Bay and the Bay of Plenty northeast of Te Kaha between 9pm Saturday and 12pm Sunday, as well as for Nelson about and southeast of Motueka including Bryant and Richmond Ranges, the Buller district, Marlborough excluding the Sounds, and North Canterbury about and north of Waimakariri River between 6am Sunday and 9am Monday.
A severe thunderstorm watch is also in place for the Bay of Plenty and Gisborne between 4am Saturday and 12pm Sunday.
MetService warned a band of rain with embedded thunderstorms may affect eastern Bay of Plenty and northern Gisborne on Sunday morning, with a moderate risk the thunderstorms could be severe with localised rainfall rates of 25-50mmh - or possibly more.
It said rainfall of that intensity could 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.
Hundreds of properties are still without power, with several small-scale outages affecting rural properties in the Far North, but the majority of homes in Northland have had their power restored.
"Our crews are continuing to work tonight, where it is safe to do so, but we have advised a small number of customers that we won't be able to get to them until tomorrow, and some repairs may take until Monday to fix," Vector said in a statement late on Saturday.
People in Auckland have also been advised to report flooding and blocked stormwater drains at 09 301 0101. Fallen trees on public property should be reported using Auckland Council's Report a Problem tool here.
