But with the bad came a good fall of snow, enough to push the freezing level as low as 1000m at Mt Ruapehu by early next week, and to even lower levels in South Island skifields.
The extreme forecast is due to a strong, moist northwest flow covering the country, which is expected to remain until an active trough moves in this weekend.
Last night, MetService had issued a severe weather watch for Buller, Marlborough, Wellington, Taranaki, Wanganui and Taihape, with heavy rain and gales forecast for the South Island and parts of the lower North Island.
A heavy rain warning was in force for Fiordland, Westland south of Otira, the Canterbury and Otago headwaters, Taranaki and the Tararua Range while a warning for severe gales is in force for Southland, Otago, Canterbury, Marlborough, Wellington and Wairarapa.
"With anything that can blow away, it's definitely worth making sure that it's tied down or secure," Mr Law said.
Heavy rain was also likely in the western Bay of Plenty ranges, and there was "moderate confidence" that this area would get a rainfall warning during today and tomorrow.
The NZ Transport Agency was urging motorists to keep an eye on the weather, especially those travelling around mountain areas and truckies, motorcyclists and people driving high-sided vehicles in regions where gales were forecast.
Auckland, with much of the upper North Island, could expect a cloudy weekend with spells of light rain or drizzle today and a period of heavier rain tomorrow.
Meanwhile, a new climate summary has painted a pleasant picture for the next three months, with the warmer-than-average winter set to roll on into spring.
According to the latest seasonal outlook, issued by the National Institute of Water and Atmospheric Research, there was now also less chance of an El Nino playing with the weather this spring, but climate scientists predict the pattern is still on its way.
The summary said temperatures in the coming three months were most likely to be above average for the east of the North Island, and average or above average for all remaining regions of New Zealand.
Cold snaps and frosts could still be expected in some parts of the country as winter advanced into spring.