However, he did not believe the front would cause significant disruption to the region because insufficient amounts of snow would fall at 500m or below to justify a warning in either northern Southland, Otago or Canterbury.
MetService meteorologist Karl Loots said the fine weather of the past few days would persist today and tomorrow for most places.
"The story of today is just a few odd showers scattered about the place, but most areas will be fine."
Whangārei, Auckland and Hamilton were all in for a day of light winds, a high of 19C and the odd coastal shower. Coromandel, Bay of Plenty around the East Cape down to Hawke's Bay would also see temperatures in the late teens, with some showers mostly about the ranges.
The high pressure driving the fine weather spell would hang in there until tomorrow evening, before a strong, cold front arrived at the bottom of the South Island.
"That will be the start of the significant weather for the week," Loots said.
By the end of Wednesday most of the South Island would be doused in rain, with the West Coast in line for the most.
Temperatures were forecast to plummet - halving in places from the start of the week - with snow possible down to 400m.
This weather pattern would persist about the South Island through to Friday, with a low pressure system arriving from the west bringing potentially more rain.
The North Island would continue its fine spell through Wednesday before the front made its way north on Thursday. Rain was forecast for most places later in the week.
Loots said at this stage the heaviest rain mid-week would affect the "usual suspects", along the South Island's West Coast.
But when the low pressure system arrived Thursday it could bring heavy rain to parts of the South Island's east coast, central parts of the country, and the North Island into Friday.
- Additional reporting Otago Daily Times
Today's weather
Whangārei
Mainly fine, apart from morning cloud. Chance afternoon shower. Light winds and afternoon sea breezes. 19C high, 9C overnight.
Auckland
Mostly sunny, with isolated afternoon showers. Light winds and afternoon sea breezes. 19C high, 10C overnight.
Hamilton
Mainly fine, but chance afternoon shower. Light winds. 19C high, 6C overnight.
Tauranga
Cloudy periods, a few evening showers. Light winds and sea breezes. 18C high, 10C overnight.
New Plymouth Fine apart from chance afternoon shower. Southeast breezes tending southwest. 17C high, 6C overnight.
Napier Some morning cloud, then fine. Light winds and sea breezes. 16C high, 5C overnight.
Whanganui A fine day. Westerly breezes. 19C high, 7C overnight.
Wellington Fine apart from some morning cloud. Northerlies becoming fresh afternoon, changing southerly overnight. 15C high, 8C overnight.
Nelson Fine. Light winds and sea breezes, southwesterlies developing evening. 16C high, 6C overnight.
Christchurch Morning cloud, then sunny spells. Light winds. 17C high, 4C overnight.
Dunedin Morning cloud and possible drizzle, then fine. Light winds. 13C high, 8C overnight.
