Enjoy the warm weather today - temperatures are forecast to plummet as a southerly storm slowly moves up the country.
The storm has already brought more than 200mm of rain to Fiordland. In the past 24 hours, Milford Sound Airport recorded five times the rainfall Auckland has received in the past month.
Nearly 170mm has fallen in Milford Sound, and more than 200mm on the even more remote Secretary Island - and more is to come, along with a cold snap.
A severe rain warning remains in place in Fiordland and Westland south of Haast to 6am and 9am tomorrow, respectively. Another 200 to 300mm of rain could fall in that time.
The warning also extends to the headwaters of the Otago lakes and rivers from 12pm today until 3pm tomorrow. This includes Wanaka and the Queenstown Lakes District.
Further north the area from Haast to Whataroa is under a heavy rain watch from tonight until tomorrow morning.
The extreme levels of rain are because of the slow-moving nature of the southerly front, MetService meteorologist Nick Zachar said.
"Tomorrow the front will try and move up a bit, but it is still sandwiched between high pressure systems to the east and the west."
Tomorrow it is forecast to slowly move up into the upper South Island, bringing rain to the Buller and Nelson regions – especially the western ranges - and scattered rain to Canterbury.
Temperatures going south
Today most of the South Island's east coast and the entire North Island are in for a fine day.
However, Dunedin was set to drop from a maximum high of 26degC today, a maximum high of 20degC tomorrow and just 13degC on Thursday, with stong or gale-force southerlies.
Queenstown could expect a high of 24degC today, but tomorrow and Thursday bring rain and highs of 18degC, and 12degC, respecrively.
Wanaka was also expected to reach 24degC today, but a cold, southeasterly change brings rain and a high of 20degC tomorrow, and just 13degC on Thursday.
Oamaru is also warm today with a forecast high of 26degC, but there's a chance of heavy rain and a high of 18degC tomorrow before strong or gale-force southerlies on Thursday and a high of just 13degC.
Invercargill will dive from maximum high of 24degC today to a maximum high of 17degC tomorrow, along with a howling southerly and rain showers, and reach just 13degC on Thursday.
In Christchurch it will be even more extreme, plummeting from 26degC today to a frigid 12degC on Thursday.
There may be a few scattered showers from Hawke's Bay around the eastern fringes to Coromandel and north of Auckland.
Tomorrow looks like more of the same, but some rain as the front moves further north in the South Island could spill into Wellington and southern Wairarapa tomorrow night.
Thursday and Friday are more uncertain regarding how far north the front travels, but it could bring rain and cloud over the North Island.
Big swells
Coming in behind the rain is a huge southern ocean swell. Open water waves as high as 10m are forecast. The heavy swells will drop by the time they reach New Zealand's coast but they could still reach 5-6m from Fiordland down to Southland tomorrow.
The system will move into the North Island late tomorrow into Thursday and even Auckland's West Coast could be in for 3-4.5m swells. These swells will be accompanied by an easterly flow moving over the North Island.
Along with the big waves, the south should also brace itself for a big drop in temperatures tomorrow and Thursday.
- NZ Herald and ODT online
