Gales ease but more rain ahead

Southerly gales and heavy rain that battered Wellington Sunday, delaying thousands of travellers, eased on Monday but the MetService said more rain was on the way.

Another front was likely to bring heavy rainfalls throughout the country over the next few days, the MetService said.

The forecast until Friday was for rain or showers for most northern and western parts of both islands.

There was a moderate risk of rainfalls exceeding warning criteria, it said.

Heaviest falls were likely on West Coast from Tuesday to Thursday, and in Buller and Nelson on Wednesday and Thursday.

Monday morning, police issued an alert warning of thick ice on South Island roads, including State Highway 1 between Dunedin and Timaru.

Motorists were advised to take care.

Wild weather on Sunday shut down ferry and air travel in and out of the capital and caused havoc on roads.

Winds of up to 148kmh forced the cancellation of 25 flights in and out of Wellington, affecting up to 1000 air travellers around the country.

Most cancelled flights at Wellington Airport were operated by the Link carriers, Air New Zealand said.

Air Nelson general manager John Hambleton said 42 Air Nelson flights in and out of Wellington were affected, as high winds were a risk to passengers disembarking aircraft.

"The problem was people being blown down as they stepped off the aircraft. It was just the nature of a particularly violent storm," Mr Hambleton said.

He said Air Nelson was able to operate aircraft to alternative airports, to get as many people as possible near to their destination.

Otherwise, passengers were rebooked on other flights or refunded.

Interislander spokesman Nigel Parry said the ferry service was expected to run more smoothly Monday.

About 900 passengers were affected on Sunday when 7m swells forced the cancellation of four morning and afternoon sailings. All passengers were given the option of catching an evening ferry or rescheduling for Monday.

The evening sailings had gone ahead slightly later than scheduled to ensure a smoother crossing.

It had still been a "little rough" but everyone who had wanted to sail Sunday had been able to, Mr Parry said.

Bluebridge ferry company cancelled three sailings, affecting about 300 passengers.

A police spokesman said it had been a busy weekend, particularly in relation to managing the roads.

Many roads had been closed due to the weather but all were open todayexcept the Paekakariki Hill Rd.

Meanwhile, South Island hydro lakes received a minor boost over the weekend as parts of Canterbury were battered by heavy rain and strong winds.

Meridian Energy spokeswoman Claire Shaw said lakes Te Anau and Manapouri had had "significant" inflow from melting snow and some rain.

Rain was falling around lakes Tekapo and Pukaki Sunday, she said, although it was not a significant amount and the effect might not be known for a few days.

Ms Shaw said power supplies through the winter should be fine but Meridian would be monitoring lake levels.

Figures from the Winter Power Group show the upper South Island achieved a 4.1 percent power saving last week compared to the same week last year. National saving was 3.6 percent.