Cold and cloudy weather due

Forecasting long range weather in winter is never easy as it chops and changes so quickly. The high, that during the weekend looking likely to roll in today, is still another day or so away. Today sees a low bringing rain and showers right across the North Island while that high slowly moves into the South Island. By Thursday both islands should see higher air pressure and therefore more settled weather with most rain clouds clearing the country. But it's now looking like the high is really going to slink past New Zealand, dropping straight down the Tasman Sea and into the Southern Ocean while a large and deep sub-tropical low forms in the northern Tasman Sea.

This low in the north is looking pretty aggressive but it should drift to the north of NZ then slip down the east coast but well out to sea. Between the high south of NZ and the low north of us it should mean a strong southerly flow spreads up the country - starting in the South Island on Friday and spreading in to the North Island on Sunday as that low slides past to the east.

That means cloudy, cold, weather will spread up the southern and eastern coastlines of both islands starting Friday and lasting until Sunday.

For northern centres, such as Auckland, it's hard to know at this early stage if the low to the north will bring in any cloud. The latest data I have shows a 60 per cent chance of cloudy weather and maybe showers on Sunday with a cold South Easterly. The weather data may change but Auckland's high for Sunday is currently just 11.

This cold southerly may also bring snow showers to low levels in southern and eastern parts of the South Island. I doubt it'll be heavy to low levels though - Saturday night/Sunday morning seem to be when the coldest air will arrive there. Certainly the chance for sleet to snow level.

In the North Island, if you're planning on skiing this week, I'd aim for Thursday, Friday or Saturday morning. Snow showers are currently forecast to arrive Saturday night and into Sunday and Monday. It may also affect the Desert Road so keep that in mind if you're travelling this weekend - highest risk times for snow are all day Sunday and Monday morning. Winds may also rise to gale force about Mt Ruapehu later on Saturday/Sunday.

I'm now finally on Twitter. I hope to provide breaking weather news via Twitter along with other weather headlines - and of course really important information such as what I ate for lunch (or didn't eat, as in yesterday's case). Technology really is amazing huh?

The weather is very changeable at the moment - certainly makes for some difficulty when planning your school holiday or weekend activities - for all the extra updates check WeatherWatch's new weather news section.

Philip Duncan