Fine and calm - for two days anyway

A ewe and her lambs joined others caught out by unseasonal snow in the central North Island. Photo / Alan Gibson

An icy blast that last week trapped motorists in the central North Island might have departed, but don't go dusting off the barbecue just yet.

Weather Watch analyst Phillip Duncan said much of the country should expect mainly fine and calm conditions today and tomorrow.

He said last week's "abnormal" snowfalls were unlikely, thanks to a large area of high pressure forming over northern parts of the country and the Tasman Sea. Northwesterly winds would also make this week warmer.

"It will still be a bit unsettled but compared to what we have had over the past two or three weeks it's probably going to be quite calm."

But there is more wet weather to come, Mr Duncan said.

"The next system will move in on Wednesday, bringing heavy rain to the South Island's west coast and probably warmer but showery for much of the rest of the country."

Metservice forecaster Paul Bruce said the front would bring possible thunderstorms for Auckland from Thursday.

He said the low weather systems coming from the Tasman Sea were not typical of spring.

"There still seems to be a tendency to get deep lows moving in from the Tasman Sea and when we get to Wednesday and Thursday we are going back to another complex trough system moving over the country."

"In fact, it looks like it will take until the end of the weekend until it moves on.

" If you can get down there, the east coast from Gisborne to Wairarapa will be quite pleasant over the next few days."

MetService's seasonal forecast said the low pressure systems from the Tasman Sea, which are expected to deepen over or to the east of New Zealand, were a pattern more commonly found in winter but these are not expected to last beyond October.

The wind flow between anticyclones and the lows should bring more frequent southwesterly or southeasterly winds, especially in eastern areas, so that air temperatures may be about to below normal this month.

Spring is typically the windiest season, with the disturbed westerly winds of the "roaring forties" at their strongest for the year and covering the whole country.

This pattern should continue in November.

MetService said these may be accompanied by a series of "boisterous" thundery fronts.